SNARE Proteins: A superfamily of small proteins which are involved in the MEMBRANE FUSION events, intracellular protein trafficking and secretory processes. They share a homologous SNARE motif. The SNARE proteins are divided into subfamilies: QA-SNARES; QB-SNARES; QC-SNARES; and R-SNARES. The formation of a SNARE complex (composed of one each of the four different types SNARE domains (Qa, Qb, Qc, and R)) mediates MEMBRANE FUSION. Following membrane fusion SNARE complexes are dissociated by the NSFs (N-ETHYLMALEIMIDE-SENSITIVE FACTORS), in conjunction with SOLUBLE NSF ATTACHMENT PROTEIN, i.e., SNAPs (no relation to SNAP 25.)Acrosome Reaction: Changes that occur to liberate the enzymes of the ACROSOME of a sperm (SPERMATOZOA). Acrosome reaction allows the sperm to penetrate the ZONA PELLUCIDA and enter the OVUM during FERTILIZATION.Acrosome: The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.Spermatozoa: Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.Sperm Capacitation: The structural and functional changes by which SPERMATOZOA become capable of oocyte FERTILIZATION. It normally requires exposing the sperm to the female genital tract for a period of time to bring about increased SPERM MOTILITY and the ACROSOME REACTION before fertilization in the FALLOPIAN TUBES can take place.Membrane Fusion: The adherence and merging of cell membranes, intracellular membranes, or artificial membranes to each other or to viruses, parasites, or interstitial particles through a variety of chemical and physical processes.R-SNARE Proteins: SNARE proteins where the central amino acid residue of the SNARE motif is an ARGININE. They are classified separately from the Q-SNARE PROTEINS where the central amino acid residue of the SNARE motif is a GLUTAMINE. This subfamily contains the vesicle associated membrane proteins (VAMPs) based on similarity to the prototype for the R-SNAREs, VAMP2 (synaptobrevin 2).IllinoisSyntaxin 1: A neuronal cell membrane protein that combines with SNAP-25 and SYNAPTOBREVIN 2 to form a SNARE complex that leads to EXOCYTOSIS.Qa-SNARE Proteins: A subfamily of Q-SNARE PROTEINS which occupy the same position as syntaxin 1A in the SNARE complex and which also are most similar to syntaxin 1A in their AMINO ACID SEQUENCE. This subfamily is also known as the syntaxins, although a few so called syntaxins are Qc-SNARES.Zona Pellucida: A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.Extracellular Signal-Regulated MAP Kinases: A mitogen-activated protein kinase subfamily that is widely expressed and plays a role in regulation of MEIOSIS; MITOSIS; and post mitotic functions in differentiated cells. The extracellular signal regulated MAP kinases are regulated by a broad variety of CELL SURFACE RECEPTORS and can be activated by certain CARCINOGENS.Mitogen-Activated Protein Kinases: A superfamily of PROTEIN-SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES, which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).Mitogen-Activated Protein Kinase 1: A proline-directed serine/threonine protein kinase which mediates signal transduction from the cell surface to the nucleus. Activation of the enzyme by phosphorylation leads to its translocation into the nucleus where it acts upon specific transcription factors. p40 MAPK and p41 MAPK are isoforms.Mitogen-Activated Protein Kinase 3: A 44-kDa extracellular signal-regulated MAP kinase that may play a role the initiation and regulation of MEIOSIS; MITOSIS; and postmitotic functions in differentiated cells. It phosphorylates a number of TRANSCRIPTION FACTORS; and MICROTUBULE-ASSOCIATED PROTEINS.Enzyme Activation: Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.Pentoxifylline: A METHYLXANTHINE derivative that inhibits phosphodiesterase and affects blood rheology. It improves blood flow by increasing erythrocyte and leukocyte flexibility. It also inhibits platelet aggregation. Pentoxifylline modulates immunologic activity by stimulating cytokine production.Chlortetracycline: A TETRACYCLINE with a 7-chloro substitution.Sperm Motility: Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.Semen Preservation: The process by which semen is kept viable outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).Sperm-Ovum Interactions: Interactive processes between the oocyte (OVUM) and the sperm (SPERMATOZOA) including sperm adhesion, ACROSOME REACTION, sperm penetration of the ZONA PELLUCIDA, and events leading to FERTILIZATION.Cryopreservation: Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.Golgi Apparatus: A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)Acrosin: A trypsin-like enzyme of spermatozoa which is not inhibited by alpha 1 antitrypsin.Sperm Head: The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.Endocannabinoids: Fatty acid derivatives that have specificity for CANNABINOID RECEPTORS. They are structurally distinct from CANNABINOIDS and were originally discovered as a group of endogenous CANNABINOID RECEPTOR AGONISTS.Sperm Immobilizing Agents: Chemical substances with sperm immobilizing activity used as topically administered vaginal contraceptives.Cannabinoid Receptor Modulators: Compounds that interact with and modulate the activity of CANNABINOID RECEPTORS.Glycerides: GLYCEROL esterified with FATTY ACIDS.Xanthophylls: Oxygenated forms of carotenoids. They are usually derived from alpha and beta carotene.Anthocidaris: A genus of SEA URCHINS in the family Echinometridae. They are closely related to and some say indistinguishable from the genus Heliocidaris.Biological Products: Complex pharmaceutical substances, preparations, or matter derived from organisms usually obtained by biological methods or assay.N-Acetyllactosamine Synthase: The A protein of the lactose synthase complex. In the presence of the B protein (LACTALBUMIN) specificity is changed from N-acetylglucosamine to glucose. EC 2.4.1.90.Galactosyltransferases: Enzymes that catalyze the transfer of galactose from a nucleoside diphosphate galactose to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.Fertilization: The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.Egg Proteins: Proteins which are found in eggs (OVA) from any species.Buffaloes: Ruminants of the family Bovidae consisting of Bubalus arnee and Syncerus caffer. This concept is differentiated from BISON, which refers to Bison bison and Bison bonasus.SUMO-1 Protein: A 1.5-kDa small ubiquitin-related modifier protein that can covalently bind via an isopeptide link to a number of cellular proteins. It may play a role in intracellular protein transport and a number of other cellular processes.Small Ubiquitin-Related Modifier Proteins: A class of structurally related proteins of 12-20 kDa in size. They covalently modify specific proteins in a manner analogous to UBIQUITIN.Sumoylation: A type of POST-TRANSLATIONAL PROTEIN MODIFICATION by SMALL UBIQUITIN-RELATED MODIFIER PROTEINS (also known as SUMO proteins).Relaxin: A water-soluble polypeptide (molecular weight approximately 8,000) extractable from the corpus luteum of pregnancy. It produces relaxation of the pubic symphysis and dilation of the uterine cervix in certain animal species. Its role in the human pregnant female is uncertain. (Dorland, 28th ed)Baccharis: A plant genus of the family ASTERACEAE. Other plants called broom include CYTISUS; SPARTIUM; and BROMUS.Protein Processing, Post-Translational: Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
(1/514) Changes in hyaluronidase, acrosin, and N-acetylhexosaminidase activities of dog sperm after incubation.

Hyaluronidase, acrosin and N-acetylhexosaminidase activities were examined in sperm collected from 12 beagle dogs and in culture medium after 0.5 hr and 7 hr of sperm incubation. The activities of the three enzymes were significantly higher at 7 hr than at 0.5 hr (P < 0.05, 0.01), and the increases were associated with sperm capacitation. It was considered that the three enzymes in the dog sperm are related to fertilization by reason of the findings of the release of these enzymes from the sperm into the medium after 7 hr of incubation.  (+info)

(2/514) Voltage-operated Ca2+ channels and the acrosome reaction: which channels are present and what do they do?

Evidence from pharmacological studies suggests that induction of the acrosome reaction of mammalian spermatozoa by solubilized zona pellucida, and possibly by progesterone, is dependent upon Ca2+ influx through voltage-operated Ca2+ channels. Studies on Ca2+ accumulation and membrane potential in ligand-stimulated or artificially depolarized spermatozoa support such a conclusion. Electrophysiological studies on rodent spermatogenic cells have revealed the presence of a 'T' type voltage-operated Ca2+ current. This current has pharmacological attributes consistent with those of the putative channel responsible for Ca2+ influx mediating the acrosome reaction. However, use of molecular techniques to study human and rodent testis and spermatogenic cells has detected the presence of three different voltage-operated Ca2+ channel subunits. One of these (alpha lE) may generate T-currents, though this is currently disputed. Voltage-operated Ca2+ channel structure and the relationship between channel subunit expression and the characteristics of consequent Ca2+ currents is briefly reviewed. The nature and function of T-channel-mediated Ca2+ influx is examined in the context of the time-course of ligand- and depolarization-induced elevation of [Ca2+]i in mammalian spermatozoa. It is likely that a secondary Ca2+ response (mobilization of stored Ca2+ or activation of a second Ca(2+)-influx pathway) is required for the acrosome reaction. Evidence for the existence and participation of various candidates is discussed (including voltage-operated Ca2+ channels, which may be functionally expressed only in mature spermatozoa), the available evidence favouring a secondary Ca(2+)-influx pathway. Immediate priorities for future research in this area are proposed.  (+info)

(3/514) Ion channels in sperm physiology.

Fertilization is a matter of life or death. In animals of sexual reproduction, the appropriate communication between mature and competent male and female gametes determines the generation of a new individual. Ion channels are key elements in the dialogue between sperm, its environment, and the egg. Components from the outer layer of the egg induce ion permeability changes in sperm that regulate sperm motility, chemotaxis, and the acrosome reaction. Sperm are tiny differentiated terminal cells unable to synthesize protein and difficult to study electrophysiologically. Thus understanding how sperm ion channels participate in fertilization requires combining planar bilayer techniques, in vivo measurements of membrane potential, intracellular Ca2+ and intracellular pH using fluorescent probes, patch-clamp recordings, and molecular cloning and heterologous expression. Spermatogenic cells are larger than sperm and synthesize the ion channels that will end up in mature sperm. Correlating the presence and cellular distribution of various ion channels with their functional status at different stages of spermatogenesis is contributing to understand their participation in differentiation and in sperm physiology. The multi-faceted approach being used to unravel sperm ion channel function and regulation is yielding valuable information about the finely orchestrated events that lead to sperm activation, induction of the acrosome reaction, and in the end to the miracle of life.  (+info)

(4/514) Detection of partial and complete acrosome reaction in human spermatozoa: which inducers and probes to use?

The acrosome reaction (AR), an essential step for achieving mammalian fertilization, was recently introduced as a means of clinical evaluation of male fertility. However, most of the available techniques for acrosomal status assessment (except those employing electron microscopy) do not define whether the measurements represent partial or complete AR. We, therefore, performed a crossover investigation of the types of inducers and probes required for detecting partial or complete AR in human spermatozoa. The acrosomal status before and after stimulation with four AR inducers was evaluated after incubation for 3 h in capacitating conditions. We used a fluorescence-activated cell sorter with fluorescein isothiocyanate-conjugated monoclonal antibody CD46 (FITC-CD46) targeting the inner acrosomal membrane for detecting a complete AR, and fluorescein isothiocyanate-Pisum sativum agglutinin (FITC-PSA) targeting the acrosomal content for detection of both partial and complete AR. Without stimulation or following stimulation with progesterone, follicular fluid (FF) or phorbol myristate ester (PMA), the AR could be detected with FITC-PSA but not with FITC-CD46. Following stimulation with the calcium ionophore A23187, the AR could be detected by both FITC-PSA and FITC-CD46. These results suggest that spontaneous AR as well as AR induced by progesterone, PMA and FF are partial. In contrast, the AR induced by A23187 is total, i.e. both partial and complete. These findings are valuable for both research and clinical purposes and are a step towards an international agreement on a standard test for human sperm AR, for which there is an urgent need.  (+info)

(5/514) Synthesis, characterization and preclinical formulation of a dual-action phenyl phosphate derivative of bromo-methoxy zidovudine (compound WHI-07) with potent anti-HIV and spermicidal activities.

In a systematic effort to develop a microbicide contraceptive capable of preventing transmission of human immunodeficiency virus (HIV), as well as providing fertility control, we have previously identified novel phenyl phosphate derivatives of zidovudine (ZDV) with 5-halo 6-alkoxy substitutions in the thymine ring and halo substitution in the phenyl moiety respectively. Here, we describe the synthesis, characterization, and successful preclinical formulation of our lead compound, 5-bromo-6-methoxy-3'-azidothymidine-5'-(p-bromophenyl) methoxyalaninyl phosphate (WHI-07), which exhibits potent anti-HIV and sperm immobilizing activities. The anti-HIV activity of WHI-07 was tested by measuring viral p24 antigen production and reverse transcriptase activity as markers of viral replication in HIV-1 infected human peripheral blood mononuclear cells (PBMC). WHI-07 inhibited replication of HIV in a concentration-dependent fashion with nanomolar IC50 values. The effects of WHI-07 on human sperm motion kinematics were analysed by computer-assisted sperm analysis (CASA), and its effects on sperm membrane integrity were examined by confocal laser scanning microscopy (CLSM), and high-resolution low-voltage scanning electron microscopy (HR-LVSEM). WHI-07 caused cessation of sperm motility in a concentration- and time-dependent fashion. The in-vitro cytotoxicities of WHI-07 and nonoxynol-9 (N-9) were compared using normal human ectocervical and endocervical epithelial cells by the MTT cell viability assay. Unlike N-9, WHI-07 had no effect upon sperm plasma and acrosomal membrane integrity. N-9 was cytotoxic to normal human ectocervical and endocervical cells at spermicidal doses, whereas WHI-07 was selectively spermicidal. The in-vivo vaginal absorption and vaginal toxicity of 2% gel-microemulsion of WHI-07 was studied in the rabbit model. The sperm immobilizing activity of WHI-07 was 18-fold more potent than that of N-9. Over a 10 day period, there was no irritation or local toxicity to the vaginal epithelia or systemic absorption of WHI-07. Therefore, as a potent anti-HIV agent with spermicidal activity, and lack of mucosal toxicity, WHI-07 may have the clinical potential to become the active ingredient of a vaginal contraceptive for women who are at high risk for acquiring HIV by heterosexual vaginal transmission.  (+info)

(6/514) Progesterone promotes the acrosome reaction in capacitated human spermatozoa as judged by flow cytometry and CD46 staining.

The acrosome reaction is a necessary prerequisite for spermatozoa to acquire fertilizing ability. Several different moieties appear to promote the acrosome reaction through different pathways, including solubilized zona pellucidae, recombinant zona protein ZP3, follicular fluid, calcium ionophores, and mannosylated bovine serum albumin (BSA). Although many investigators have presented evidence that progesterone also promotes the acrosome reaction through the mediation of a non-genomic cell membrane receptor, this concept has been challenged. Other workers have suggested that progesterone does not promote an acrosome reaction in human spermatozoa, as judged by the detection of CD46, a complement regulatory protein present on the inner acrosome membrane, through flow cytometric analysis of large numbers of spermatozoa. Prior investigations were criticized by the limited numbers of spermatozoa enumerated visually, the use of non-specific staining techniques, and the failure to eliminate dead spermatozoa during the scoring of the acrosome reaction. We have repeated these experiments, using both a supravital dye to eliminate dead spermatozoa from flow cytometric analysis, and anti-CD46 monoclonal antibody to score acrosome-reacted spermatozoa. Care was taken to validate the adequacy of capacitation conditions, which were proven by the ability of spermatozoa to acrosome react in response to mannosylated BSA and to penetrate zona-free hamster eggs. Confocal microscopy was used to confirm that CD46 immunostaining was limited to the acrosomal region of the spermatozoon head. Our results indicate that progesterone does promote an acrosome reaction within capacitated spermatozoa.  (+info)

(7/514) Characterization of human zona pellucida glycoproteins.

The human egg may only be fertilized by one spermatozoon to prevent polyploidy. In most mammals, the primary block to polyspermy occurs at the zona pellucida (ZP). Little is known of the human ZP and the changes occurring following fertilization to prevent polyploidy. Using antibodies directed against synthetic peptides predicted from the human ZP2 and ZP3 cDNA, we identified ZP3 as a 53-60 kDa glycoprotein and ZP2 as a 90-110 kDa glycoprotein in prophase-I oocytes. Characterization of the ZP from metaphase II arrested eggs (inseminated-unfertilized and fertilized-uncleaved), shows no visible modification of ZP3, but demonstrates that ZP2 undergoes limited proteolysis in the amino terminal domain, to a 60-73 kDa species, denoted ZP2p, which remains linked to the proteolysed fragments by intramolecular disulphide bonds. A lack of ZP2 proteolytic activity in acrosomal supernatants is consistent with an oocyte origin for the protease. The ZP2-specific protease may be released during cortical granule exocytosis which occurs during meiotic maturation and following sperm-egg fusion as part of the block to polyspermy. Since mouse ZP2 acts as a secondary sperm receptor, it is possible that intact ZP2 binds a secondary egg binding protein, whereas cleaved ZP2 does not, suggesting a possible mechanism for the block to polyspermy.  (+info)

(8/514) Identification of Rab3A GTPase as an acrosome-associated small GTP-binding protein in rat sperm.

The acrosome reaction is a membrane fusion event that is prerequisite for sperm penetration through the zona pellucida. To elucidate the molecular mechanisms involved in membrane fusion, the expression and localization of Rab proteins, a subfamily of small GTPases that have been shown to play key roles in regulation of intracellular membrane traffic and exocytosis, were examined in rat testis and sperm. Reverse transcription polymerase chain reaction, immunoblot analysis, and immunofluorescence microscopy revealed that Rab3A protein, which is thought to be involved in regulation of exocytosis in neurons and endocrine cells, is associated with the sperm acrosome. The protein was undetectable in acrosome-free heads prepared by sucrose density gradient centrifugation. Immunogold electron microscopy performed on ultrathin cryosections provided further evidence that Rab3A protein is associated with the acrosomal membrane. Acrosome reaction assays revealed that synthetic peptide of the Rab3 effector domain inhibited acrosomal exocytosis triggered by calcium ionophore A23187 in a concentration-dependent fashion, suggesting that Rab3A acts as an inhibitory regulator in the acrosome reaction. In view of the putative role of Rab3A protein in membrane fusion systems, these results suggest that Rab3A could be involved in regulating the mammalian acrosome reaction by controlling the membrane fusion system in sperm.  (+info)

*  Sperm-associated antigen 8
2007). "Inhibition of mouse acrosome reaction and sperm-zona pellucida binding by anti-human sperm membrane protein 1 antibody ...
*  Acrosome reaction
Therefore, sperm cells go through a process known as the acrosome reaction which is the reaction that occurs in the acrosome of ... which is necessary for initiating the acrosome reaction, the membrane surrounding the acrosome fuses with the plasma membrane ... Since the acrosome reaction has already occurred, sperm are then able to penetrate the zona pellucida due to mechanical action ... The acrosome reaction can be stimulated in vitro by substances a sperm cell may encounter naturally such as progesterone or ...
*  Hyperactivation
... could then be followed by the acrosome reaction where the cap-like structure on the head of the cell releases ... Some definitions consider sperm activation to consist of these two processes of hyperactivation and the acrosome reaction ...
*  Egg jelly
"Egg-jelly signal molecules for triggering the acrosome reaction in starfish spermatozoa". The International Journal of ... The sulfated fucan glycoproteins play an important role in binding to sperm receptors and triggering the acrosomal reaction. ...
*  Biochemical cascade
Phospholipase C (PLC) is involved in acrosome reaction. ZP3 is a glycoprotein present in zona pelucida and it interacts with ... To have the ability to fertilize the female gamete, this cell suffers capacitation and acrosome reaction in female reproductive ... This hormone activates AKT that leads to activation of other protein kinases, involved in capacitation and acrosome reaction. ... Gupta, SK; Bhandari, B (Jan 2011). "Acrosome reaction: relevance of zona pellucida glycoproteins". Asian Journal of Andrology. ...
*  Intracytoplasmic sperm injection
This is due to the fact that in IVF acrosome reaction has to take place and thousands of sperm cells have to be involved. Once ... With this method acrosome reaction is skipped. There are several differences within classic IVF and ICSI. However, the steps to ...
*  Hamster zona-free ovum test
This test evaluates the acrosome reaction of human spermatozoa. However, the incidence of acrosome reaction in freely swimming ... Yang, YS; Rojas, FJ; Stone, SC (Dec 1988). "Acrosome reaction of human spermatozoa in zona-free hamster egg penetration test". ...
*  SYT6
"Synaptotagmin VI participates in the acrosome reaction of human spermatozoa". Developmental Biology. 235 (2): 521-9. doi: ...
*  Spermatozoon
The second process in sperm activation is the acrosome reaction. This involves releasing the contents of the acrosome, which ... There is some evidence that this binding is what triggers the acrosome to release the enzymes that allow the sperm to fuse with ... Above the nucleus lies a cap-like structure called the acrosome, formed by modification of the Golgi body and which secretes ...
*  Acrosin
... is released from the acrosome of spermatozoa as a consequence of the acrosome reaction. It aids in the penetration of ... Upon stimulus, the acrosome releases its contents onto the zona pellucida. After this reaction occurs, the zymogen form of the ... Thus, some argue for its role in assisting in the dispersal of acrosomal contents following the acrosome reaction, while others ... The importance of acrosin in the acrosome reaction has been contested. It has been found through genetic knockout experiments ...
*  Pablo Visconti
"Roles of Bicarbonate, cAMP, and Protein Tyrosine Phosphorylation on Capacitation and the Spontaneous Acrosome Reaction of ... "Analysis of CAPZA3 localization reveals temporally discrete events during the acrosome reaction". Journal of Cellular ...
*  Zona pellucida
This structure binds spermatozoa, and is required to initiate the acrosome reaction. In the mouse (the best characterised ... ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the contents of the acrosomal ... ZP3 and ZP4 bind to capacitated spermatozoa and induce the acrosome reaction. Successful fertilization depends on the ability ...
*  ACRV1
1995). "Human SP-10: acrosomal distribution, processing, and fate after the acrosome reaction". Biol. Reprod. 51 (6): 1222-31. ...
*  Fertilisation
After the acrosome reaction, the sperm is believed to remain bound to the zona pellucida through exposed ZP2 receptors. These ... In mammals, the binding of the spermatozoon to the GalT initiates the acrosome reaction. This process releases the ... to the N-acetylglucosamine residues on the ZP3 and is important for binding with the sperm and activating the acrosome reaction ... Unlike sea urchins, the sperm binds to the egg before the acrosomal reaction. ZP3, a glycoprotein in the zona pellucida, is ...
*  SPA17
"Sequence of a rabbit sperm zona pellucida binding protein and localization during the acrosome reaction". Dev. Biol. 165 (2): ...
*  Capacitation
Cortical reaction Acrosome reaction Essential Reproduction, Johnson, 6th edition, Blackwell Publishing Lozano G.M., Bejarano, I ... After this capacitation, the sperm must undergo the final maturation step, activation, involving the acrosome reaction. ...
*  Phospholipase A2
"Group X phospholipase A2 is released during sperm acrosome reaction and controls fertility outcome in mice". The Journal of ... Increase in phospholipase A2 activity is an acute-phase reaction that rises during inflammation, which is also seen to be ...
*  Sardul Singh Guraya
... sperm capacitation and acrosome reaction in the excised reproductive tract of hamsters". Theriogenology. 44 (4): 599-608. doi: ...
*  Reproductive immunology
Normally, spermatozoa fuse with the zona pellucida surrounding the mature oocyte; the resulting acrosome reaction breaks down ...
*  Carl H. Johnson
Heavy metal chelators prolong motility and viability of sea urchin sperm by inhibiting spontaneous acrosome reactions. J. Exp. ...
*  Hyaluronidase
Once this occurs, the sperm is capable of binding with the zona pellucida, and the acrosome reaction can occur. Meyer, K (1971 ... In most mammalian fertilization, hyaluronidase is released by the acrosome of the sperm cell after it has reached the oocyte, ... a scheme based on the enzyme reaction products. The three main types of hyaluronidases are two classes of eukaryotic ...
*  Human fertilization
The cortical reaction and acrosome reaction are both essential to ensure that only one sperm will fertilize an egg. After the ... preparing it for the acrosome reaction, the enzymatic penetration of the egg's tough membrane, the zona pellucida, which ... In preparation for the fusion of their genetic material both the oocyte and the sperm undergo transformations as a reaction to ... Upon encountering the secondary oocyte, the acrosome of the sperm produces enzymes which allow it to burrow through the outer ...
*  Sialyl-Lewis X
"Effects of Native Human Zona Pellucida Glycoproteins 3 and 4 on Acrosome Reaction and Zona Pellucida Binding of Human ...
*  AKAP3
It may function as a regulator of both motility- and head-associated functions such as capacitation and the acrosome reaction. ...
*  ZP3
2007). "Acrosome reaction induced by recombinant human zona pellucida 3 peptides rhuZP3a22 approximately 176 and rhuZP3b177 ... 2008). "Effects of native human zona pellucida glycoproteins 3 and 4 on acrosome reaction and zona pellucida binding of human ... gene is a major structural component of the ZP and functions in primary binding and stimulation of the sperm acrosome reaction ...
*  ADCY10
... and/or the acrosome reaction. Mutations in the ADCY10 gene are associated with an increased risk of adsorptive hypercalciuria. ...
During synaptic vesicle fusion, the soluble N-ethylmaleimide-sensitive factor-attachment protein receptor (SNARE) protein syntaxin-1 exhibits two conformations that both bind to Munc18-1: a "closed" conformation outside the SNARE complex and an "open" conformation in the SNARE complex. Although SNARE complexes containing open syntaxin-1 and Munc18-1 are essential for exocytosis, the function of closed syntaxin-1 is unknown. We generated knockin/knockout mice that expressed only open syntaxin-1B. Syntaxin-1BOpen mice were viable but succumbed to generalized seizures at 2 to 3 months of age. Binding of Munc18-1 to syntaxin-1 was impaired in syntaxin-1BOpen synapses, and the size of the readily releasable vesicle pool was decreased; however, the rate of synaptic vesicle fusion was dramatically enhanced. Thus, the closed conformation of syntaxin-1 gates the initiation of the synaptic vesicle fusion reaction, which is then mediated by SNARE-complex/Munc18-1 assemblies. ...
The soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (SNARE) protein syntaxin‐1 adopts a closed conformation when bound to Munc18‐1, preventing binding to synaptobrevin‐2 and SNAP‐25 to form the ternary SNARE complex. Although it is known that the MUN domain of Munc13‐1 catalyzes the transition from the Munc18‐1/syntaxin‐1 complex to the SNARE complex, the molecular mechanism is unclear. Here, we identified two conserved residues (R151, I155) in the syntaxin‐1 linker region as key sites for the MUN domain interaction. This interaction is essential for SNARE complex formation in vitro and synaptic vesicle priming in neuronal cultures. Moreover, this interaction is important for a tripartite Munc18‐1/syntaxin‐1/MUN complex, in which syntaxin‐1 still adopts a closed conformation tightly bound to Munc18‐1, whereas the syntaxin‐1 linker region changes its conformation, similar to that of the LE mutant of syntaxin‐1 when bound to Munc18‐1. We ...
The soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (SNARE) protein syntaxin‐1 adopts a closed conformation when bound to Munc18‐1, preventing binding to synaptobrevin‐2 and SNAP‐25 to form the ternary SNARE complex. Although it is known that the MUN domain of Munc13‐1 catalyzes the transition from the Munc18‐1/syntaxin‐1 complex to the SNARE complex, the molecular mechanism is unclear. Here, we identified two conserved residues (R151, I155) in the syntaxin‐1 linker region as key sites for the MUN domain interaction. This interaction is essential for SNARE complex formation in vitro and synaptic vesicle priming in neuronal cultures. Moreover, this interaction is important for a tripartite Munc18‐1/syntaxin‐1/MUN complex, in which syntaxin‐1 still adopts a closed conformation tightly bound to Munc18‐1, whereas the syntaxin‐1 linker region changes its conformation, similar to that of the LE mutant of syntaxin‐1 when bound to Munc18‐1. We ...
In this study, we demonstrated that tomosyn regulates the oligomerization of the SNARE complex and inhibits SNARE-dependent neurotransmitter release. We reconstituted tomosyn-induced oligomerization of the SNARE complex in vitro and showed that the WD-40 repeat domain of tomosyn has an intrinsic ability to catalyze the oligomerization of the SNARE complex. It was previously reported that the C-terminal VLD of tomosyn acts as a SNARE domain competing with VAMP-2 and thereby inhibiting the formation of the SNARE complex (Yokoyama et al., 1999; Pobbati et al., 2004). Consistent with these studies, our in vitro assay showed that the C-terminal VLD of tomosyn inhibits the formation of the SNARE complex. Therefore, we concluded that tomosyn potently inhibits SNARE-dependent synaptic vesicle fusion via both N-terminal WD-40 repeat domain-catalyzed oligomerization of the SNARE complex and C-terminal VLD-based competitive inhibition of SNARE complex formation.. Synaptic efficacy at mossy fiber synapses ...
The principal role of SNARE proteins is to arbitrate vesicle fusion to a target membrane. Formation of tripartite SNARE protein complexes between SNARE proteins on opposing membranes is the minimal requirement for membrane fusion. The SNARE protein family is large, consisting of more than 60 members. A member of the SNARE family, syntaxin, is found on the sperm plasma membrane while synaptobrevin, is found on the outer acrosomal membrane. During the sperm acrosome reaction, the outer acrosomal membrane fuses at hundreds of points with the overlying plasma membrane, resulting in release of the acrosomal contents. We hypothesize that syntaxin and synaptobrevin re-localize within the sperm plasma membrane prior to the acrosome reaction to form SNARE complexes and promote membrane fusion at hundreds of specific points. Immunofluorescence was used to localize both syntaxin and synaptobrevin in mouse epididymal sperm before and after capacitation. Sperm were fixed and incubated with antibodies to ...
TY - JOUR. T1 - Synaptic vesicle exocytosis. AU - Südhof, Thomas C.. AU - Rizo-Rey, Jose. PY - 2011/12. Y1 - 2011/12. N2 - Presynaptic nerve terminals release neurotransmitters by synaptic vesicle exocytosis. Membrane fusion mediating synaptic exocytosis and other intracellular membrane traffic is affected by a universal machinery that includes SNARE (for "soluble NSF-attachment protein receptor") and SM (for "Sec1/Munc18-like") proteins. During fusion, vesicular and target SNARE proteins assemble into an a-helical trans-SNARE complex that forces the two membranes tightly together, and SM proteins likely wrap around assembling trans- SNARE complexes to catalyze membrane fusion. After fusion, SNARE complexes are dissociated by the ATPase NSF (for "N-ethylmaleimide sensitive factor"). Fusion-competent conformations of SNARE proteins are maintained by chaperone complexes composed of CSPa, Hsc70, and SGT, and by nonenzymatically acting synuclein chaperones; dysfunction of these chaperones results ...
Munc18-1 plays a crucial role in regulated exocytosis in neurons and neuroendocrine cells through modulation of vesicle docking and membrane fusion. The molecular basis for Munc18 function is still unclear, as are the links with Rabs and SNARE [SNAP (soluble N-ethylmaleimide-sensitive factor-attachment protein) receptor] proteins that are also required. Munc18-1 can bind to SNAREs through at least three modes of interaction, including binding to the closed conformation of syntaxin 1. Using a gain-of-function mutant of Munc18-1 (E466K), which is based on a mutation in the related yeast protein Sly1p, we have identified a direct interaction of Munc18-1 with Rab3A, which is increased by the mutation. Expression of Munc18-1 with the E466K mutation increased exocytosis in adrenal chromaffin cells and PC12 cells (pheochromocytoma cells) and was found to increase the density of secretory granules at the periphery of PC12 cells, suggesting a stimulatory effect on granule recruitment through docking or ...
In this study we show using in vitro and in vivo approaches that in neuroendocrine cells munc18-1 has two modes of binding to syntaxin 1a. I show that munc 18-1 plays a vital role in binding to a closed-form of syntaxin 1a, keeping syntaxin 1a inactive and permitting its trafficking to the plasma membrane. Munc18-1 is also able to bind to an active open form of syntaxin 1a, allowing it to bind to other SNAREs. I demonstrate that in the absence of munc 18-1, syntaxin 1a and SNAP-25 can readily interact in the Golgi complex, forming reactive SNARE complexes that fail to traffic to plasma membrane. The exocytotic SNARE proteins are highly promiscuous in their interactions with other SNAREs, and thus it is essential to traffic the exocytotic SNARE proteins through intracellular compartments while avoiding ectopic interactions between non-cognate SNARE proteins. Munc 18-1 has a vital regulatory role in preventing the formation of the binary complex between syntaxin 1a and SNAP-25 before the proteins ...
Current Research: Microbial manipulation of host SNARE machinery is an emerging field in cellular microbiology. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) proteins mediate specific vesicular fusion events. Recently, SNARE proteins have been linked to the development of specialized intracellular niches critical to some intracellular bacteria. My research focuses on understanding the mechanisms which the obligate intracellular pathogen Chlamydia trachomatis employs to hijack metabolites from the host cell. C. trachomatis is associated with blinding trachoma and is the most common bacterially associated sexually transmitted disease. C. trachomatis is an obligate intracellular bacterium that replicates within a parasitophorous vacuole termed an inclusion.. The mechanisms by which the inclusion membrane, and thus, chlamydiae obtain nutrients are poorly understood. To examine Golgi-derived vectoral trafficking to the chlamydial inclusion, we developed a polarized ...
TY - JOUR. T1 - Exocytosis and synaptic vesicle function. AU - Shin, Ok Ho. PY - 2014. Y1 - 2014. N2 - Synaptic vesicles release their vesicular contents to the extracellular space by Ca2+-triggered exocytosis. The Ca2+-triggered exocytotic process is regulated by synaptotagmin (Syt), a vesicular Ca2+-binding C2 domain protein. Synaptotagmin 1 (Syt1), the most studied major isoform among 16 Syt isoforms, mediates Ca2+-triggered synaptic vesicle exocytosis by interacting with the target membranes and SNARE/complexin complex. In synapses of the central nervous system, synaptobrevin 2, a major vesicular SNARE protein, forms a ternary SNARE complex with the plasma membrane SNARE proteins, syntaxin 1 and SNAP25. The affinities of Ca2+-dependent interactions between Syt1 and its targets (i.e., SNARE complexes and membranes) are well correlated with the efficacies of the corresponding exocytotic processes. Therefore, different SNARE protein isoforms and membrane lipids, which interact with Syt1 with ...
Cytotoxic T lymphocytes (CTLs) kill target cells by secretion of cytotoxic components such as perforin and granzymes which are contained in lytic granules. Fusion of lytic granules occurs at the contact zone between the target cell and the CTL, the immunological synapse (IS). T cell receptor (TCR) enrichment at the IS is one of the key early events of IS formation. Soluble NSF attachment receptor (SNARE) proteins are required for all fusion events in cells, but the individual SNARE proteins that are important for CTL function are not yet known. We identified syntaxin 7 in CTLs by reverse transcriptase PCR and immunocytochemistry. We found that syntaxin 7 is localised to the IS with a similar distribution to the lytic granule marker - perforin. We then blocked the function of syntaxin 7 by deleting its transmembrane domain and observed a complete loss of TCR accumulation at the IS, indicating that no IS is formed. These results imply that syntaxin 7 is required for IS formation in CTLs. Further ...
Properly regulated exocytosis of neurotransmitters and hormones from membrane-delimited vesicles is essential for normal cellular function. At least 3 distinct steps are involved in regulated exocytosis: (1) the docking of vesicles at the appropriate plasma membrane, (2) priming of a subset of docked vesicles to become release-competent, i.e. able to release in response to a stimulus without further maturation steps, and (3) the fusion of the vesicle membrane with the plasma membrane, during which a fusion pore forms and dilates to release vesicle contents. A current working model to explain these steps in molecular terms is the SNARE hypothesis, which postulates that the vesicle membrane and the plasma membrane are brought into close proximity and triggered to fuse with each other by forming a stable SNARE core complex from the SNARE proteins on their membranes. Complexin, a small neuronal protein that binds to the assembled SNARE core complex, has been suggested to regulate neurotransmitter ...
TY - JOUR. T1 - Copper blocks V-ATPase activity and SNARE complex formation to inhibit yeast vacuole fusion. AU - Miner, Gregory E.. AU - Sullivan, Katherine D.. AU - Zhang, Chi. AU - Hurst, Logan R.. AU - Starr, Matthew L.. AU - Rivera-Kohr, David A.. AU - Jones, Brandon C.. AU - Guo, Annie. AU - Fratti, Rutilio. PY - 2019/11/1. Y1 - 2019/11/1. N2 - The accumulation of copper in organisms can lead to altered functions of various pathways and become cytotoxic through the generation of reactive oxygen species. In yeast, cytotoxic metals such as Hg+, Cd2+ and Cu2+ are transported into the lumen of the vacuole through various pumps. Copper ions are initially transported into the cell by the copper transporter Ctr1 at the plasma membrane and sequestered by chaperones and other factors to prevent cellular damage by free cations. Excess copper ions can subsequently be transported into the vacuole lumen by an unknown mechanism. Transport across membranes requires the reduction of Cu2+ to Cu+. Labile ...
The botulinum toxin as a therapeutic agent: molecular and pharmacological insights Roshan Kukreja,1 Bal Ram Singh2 1Department of Chemistry and Biochemistry, University of Massachusetts, 2Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA, USA Abstract: Botulinum neurotoxins (BoNTs), the most potent toxins known to mankind, are metalloproteases that act on nerve–muscle junctions to block exocytosis through a very specific and exclusive endopeptidase activity against soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins of presynaptic vesicle fusion machinery. This very ability of the toxins to produce flaccid muscle paralysis through chemical denervation has been put to good use, and these potentially lethal toxins have been licensed to treat an ever expanding list of medical disorders and more popularly in the field of esthetic medicine. In most cases, therapeutic BoNT preparations are high-molecular-weight protein complexes consisting of
Munc18b regulates core SNARE complex assembly and constitutive exocytosis by interacting with the N-peptide and the closed-conformation C-terminus of syntaxin ...
In eukaryotic cells, membrane-bound vesicles carry cargo between intracellular compartments, to and from the cell surface, and to the extracellular environment. Many conserved families of proteins are required for properly localized vesicle fusion, including the multi-subunit tethering complexes and the SNARE complexes. These protein complexes work together to promote proper vesicle fusion in other trafficking pathways. Contrary to these other pathways, our lab previously suggested that the exocyst subunit Sec6, a component of the exocytosis-specific tethering complex, inhibited Sec9:Sso1 SNARE complex assembly due to interactions in vitro with the SNARE protein Sec9 (Sivaram et al., 2005). My goal for this project was to test the hypothesis that Sec6 inhibited SNARE complex assembly in vivo. I therefore chose to generate Sec6:Sec9 loss-of-binding mutants, and study their effect both in vitro and in vivo. I identified a patch of residues on Sec9 that, when mutated, are sufficient to disrupt the novel
Background Botulism, an fatal neuroparalytic disease often, is caused by botulinum neurotoxins (BoNT) which consist of a family of seven serotypes (A-H) produced by the anaerobic bacterium and [2]. Hc functions by binding nerve cells and facilitates the internalization of the Lc, a zinc endopeptidase that cleaves SNARE (soluble N-ethylmaleimide sensitive factor attachment receptor) proteins. This action prevents the release of acetylcholine from the neuron into the neuromuscular junction, ultimately resulting in flaccid paralysis of the muscle [5], [6]. The three-dimensional structure of the BoNT/A holotoxin has been determined at 3.3 ? resolution [7]. In mice, Zanamivir an LD50 of 10 pg per organism was reported for BoNT/A when administered by inter-peritoneal injection [8]. Early studies estimated a minimum human lethal dose (LD100) of BoNT/A at 1 ng per kg body mass when administered via inter-peritoneal injection [9], but it has since been recognized that the route of toxin exposure is ...
Biochemical analysis of SNARE protein interactions [Elektronische Ressource] : role of transmembrane domain / presented by Rana Roy : Dissertation Submitted to the Combined Faculties for the Natural Sciences and for Mathematics of the Ruperto-Carola University of Heidelberg, Germany for the degree of Doctor of Natural Sciences Presented by Rana Roy Diplom - M.Sc. in Biochemistry from University of Calcutta, India Born in: Purulia, India Oral examination: Thesis Title Biochemical Analysis of SNARE Protein
SNARE proteins participate in recognition and fusion of membranes. A SNARE complex consisting of vti1b, syntaxin 8, syntaxin 7, and endobrevin/VAMP-8 which is required for fusion of late endosomes in vitro has been identified recently. Here, we generated mice deficient in vti1b to study the function of this protein in vivo. vti1b-deficient mice had reduced amounts of syntaxin 8 due to degradation of the syntaxin 8 protein, while the amounts of syntaxin 7 and endobrevin did not change. These data indicate that vti1b is specifically required for the stability of a single SNARE partner. vti1b-deficient mice were viable and fertile. Most vti1b-deficient mice were indistinguishable from wild-type mice and did not display defects in transport to the lysosome. However, 20% of the vti1b-deficient mice were smaller. Lysosomal degradation of an endocytosed protein was slightly delayed in hepatocytes derived from these mice. Multivesicular bodies and autophagic vacuoles accumulated in hepatocytes of some ...
How is Vesicle-Associated Membrane Protein 1 abbreviated? VAMP1 stands for Vesicle-Associated Membrane Protein 1. VAMP1 is defined as Vesicle-Associated Membrane Protein 1 somewhat frequently.
N-Ethyl-maleimide-sensitive factor (NSF) plays a critical role in the regulation of exocytosis. NSF regulates exocytosis by interacting with a complex containing soluble NSF attachment protein receptor (SNARE) molecules, hydrolyzing ATP, and disassembling the SNARE complex. We hypothesized that peptide inhibitors of NSF would decrease exocytosis. We now report the development of a novel set of peptides that block exocytosis by inhibiting NSF activity. These NSF inhibitors are fusion polypeptides composed of an 11 amino acid human immunodeficiency virus transactivating regulatory protein (TAT) domain fused to a 22 amino acid NSF domain. These TAT-NSF fusion polypeptides cross endothelial cell membranes, inhibit NSF hydrolysis of ATP, decrease NSF disassembly of SNARE molecules, and block exocytosis of von Willebrand factor. Control peptides have no effect on exocytosis. TAT-NSF inhibitors administered to mice prolong the bleeding time. Blood concentrations of these TAT-NSF peptides rapidly ...
Membrane fusion reactions have been reconstituted in vitro, but often the reconstituted reactions have not directly mirrored the requirements for synaptic vesicle fusion in vivo. Previous work generally used only N-ethylmaleimide-sensitive factor (NSF) attachment protein SNAP receptors (SNAREs) and one or two additional components and could not explain why deletion of Munc18-1 or Munc13 abolishes neurotransmitter release completely, yielding the severe disruptions of synaptic vesicle release in knockout mouse. Ma et al. (see the Perspective by Hughson) now present a faithful reconstitution of synaptic vesicle fusion. Membrane fusion required Munc18-1 and Munc13 when the reconstitution experiments included all eight key components (three SNAREs, Munc18-1, Munc13, synaptotagmin-1, NSF, and α-SNAP). C. Ma, L. Su, A. B. Seven, Y. Xu, J. Rizo, Reconstitution of the vital functions of Munc18 and Munc13 in neurotransmitter release. Science 339, 421-425 (2013). [Abstract] [Full Text] F. M. Hughson, ...
Sec1p/Munc18 (SM) proteins are believed to play an integral role in vesicle transport through their interaction with SNAREs. Different SM proteins have been shown to interact with SNAREs via different mechanisms, leading to the conclusion that their function has diverged. To further explore this notion, in this study, we have examined the molecular interactions between Munc18c and its cognate SNAREs as these molecules are ubiquitously expressed in mammals and likely regulate a universal plasma membrane trafficking step. Thus, Munc18c binds to monomeric syntaxin4 and the N-terminal 29 amino acids of syntaxin4 are necessary for this interaction. We identified key residues in Munc18c and syntaxin4 that determine the N-terminal interaction and that are consistent with the N-terminal binding mode of yeast proteins Sly1p and Sed5p. In addition, Munc18c binds to the syntaxin4/SNAP23/VAMP2 SNARE complex. Pre-assembly of the syntaxin4/Munc18c dimer accelerates the formation of SNARE complex compared to assembly
Synaptic vesicle fusion is at least in part mediated by the assembly of three synaptic SNARE proteins-the vesicle protein synaptobrevin/VAMP and the plasma membrane proteins SNAP-25 and syntaxin/HPC-1-into a tight complex. Syntaxin also interacts with another essential fusion protein, Munc18-1. SNARE proteins and Munc18-1 perform multiple functions that are exquisitely regulated. For example, during fusion, syntaxin changes from a closed into an open conformation. We recently showed in mice that permanent "opening" of syntaxin by mutagenesis destabilizes synapses, leading to massive epilepsy. As another example, synaptobrevin is required for both spontaneous and evoked synaptic vesicle fusion, but recent data reveal that the mechanisms by which synaptobrevin acts in these two forms of fusion differ. In addition to this dual function in exocytosis, synaptobrevin is also required for normal fast endocytosis of vesicles. These findings suggest an unexpectedly economical organization of the ...
Once you have navigated to the collection online narratives, you will be able to scroll through images of all Snares flowering plants and most ferns, to the right of the featured image, within each narrative.. Within the Bryophyte & lichen narrative, you will able to click on 16 images, found below the main text, which link to collection objects. An inventory of Snares Islands bryophytes based on all known collections is in progress, so watch this space!. Thanks to Leon Perrie for co-authoring the ferns narrative and The Department of Conservation, who made our work on the Snares Islands possible.. Other blogs in this series:. Botany Collection Narratives (Part 3): Image highlights from Hue te Taka (Moa Point) Narrative. Botany Collection Narratives (Part 2): Lindauer, Algae Nova-Zelandicae Exsiccatae. Botany Collection Narratives (Part 1): Recent Botany Donations. ...
Fig. 2. Stages involved in vesicle-membrane fusion and key proteins involved. The proteins in the central schematic are color coded as follows: synaptobrevin, dark blue; synaptophysin, light blue; syntaxin, red; nSec1, brown; SNAP-25, green; synaptotagmin, yellow; Rab3A, dark red circle; rabphilin-3A, olive green; Ca2+ channel, magenta; NSF, pink circle; α-SNAP, sky blue. Surrounding the schematic are crystal structures of the SNARE complex (blue: synaptobrevin; red: syntaxin; green: SNAP-25) [29], the N-terminal domain of syntaxin, which is shown as a separate structure (the structure of the linker between the syntaxin N-terminal domain and the core SNARE complex is unknown) [30], the nSec1-syntaxin complex (red: syntaxin; brown: nSec1) [38••], α-SNAP (Sec17 in yeast) [110••], NSF-N[106••.] and [107••.], NSF-D2 [103.] and [104.], the complex between the small G protein Rab3A and the effector binding domain of rabphilin-3A (red: Rab3A; brown: rabphilin-3A) [92••], Rab GDI ...
article{61832d71-ce27-47ca-90bf-cd6413a507cf, abstract = {,p,Ca,sup,2+,/sup,-sensor proteins are generally implicated in insulin release through SNARE interactions. Here, secretagogin, whose expression in human pancreatic islets correlates with their insulin content and the incidence of type 2 diabetes, is shown to orchestrate an unexpectedly distinct mechanism. Single-cell RNA-seq reveals retained expression of the TRP family members in β-cells from diabetic donors. Amongst these, pharmacological probing identifies Ca,sup,2+,/sup,-permeable transient receptor potential vanilloid type 1 channels (TRPV1) as potent inducers of secretagogin expression through recruitment of Sp1 transcription factors. Accordingly, agonist stimulation of TRPV1s fails to rescue insulin release from pancreatic islets of glucose intolerant secretagogin knock-out(,sup,-/-,/sup,) mice. However, instead of merely impinging on the SNARE machinery, reduced insulin availability in secretagogin,sup,-/-,/sup, mice is due to ...
Neurons depend upon neurotransmitter release through regulated exocytosis to accomplish the immense processing performed within the central nervous system. The SNARE hypothesis points to a family of proteins that are thought to enable the membrane fusion that leads to exocytosis. The secondary structure of SNAP-25 is unique among SNARE proteins in that it has two alpha helical SNARE motifs and a cysteine rich (C85, C88, C90, C92) membrane interacting region but notransmembrane domain. The cysteines may be modified by palmitoylation or oxidation but the role of these modifications in vivo is not well understood. Our goal is to elucidate possible regulatory roles of SNAP-25 that relate to its unique structure and these reversible modifications. However, the study of SNAP-25 in reconstituted systems is hampered by a lack of readily available palmitoylated SNAP-25. A method for in vitro palmitoylation of SNAP-25 by HIP14, a neuronal acyltransferase, is described along with the application of a ...
Neurons depend upon neurotransmitter release through regulated exocytosis to accomplish the immense processing performed within the central nervous system. The SNARE hypothesis points to a family of proteins that are thought to enable the membrane fusion that leads to exocytosis. The secondary structure of SNAP-25 is unique among SNARE proteins in that it has two alpha helical SNARE motifs and a cysteine rich (C85, C88, C90, C92) membrane interacting region but notransmembrane domain. The cysteines may be modified by palmitoylation or oxidation but the role of these modifications in vivo is not well understood. Our goal is to elucidate possible regulatory roles of SNAP-25 that relate to its unique structure and these reversible modifications. However, the study of SNAP-25 in reconstituted systems is hampered by a lack of readily available palmitoylated SNAP-25. A method for in vitro palmitoylation of SNAP-25 by HIP14, a neuronal acyltransferase, is described along with the application of a biotinylation
The available database information concerning Rab17 and its interactors is insufficient to infer potential effectors and pathways through which this GTPase acts to suppress cancer invasiveness and progression. We, therefore, determined the Rab17 interactome and its influence on the cellular proteome in an unbiased manner. The use of high-accuracy MS-based approaches has enabled us to do this and to show that Rab17 has a close physical and functional relationship with the SNARE protein Vamp8. Rab GTPases are known to recruit specific effector proteins that bind to SNAREs, giving specificity to vesicle fusion (Angers and Merz, 2011). Nevertheless, to our knowledge, our study is the first to provide an indication that the stability and cellular levels of a SNARE protein may be controlled by a Rab GTPase. Moreover, because Vamp8 is the only component of the proteome that is significantly altered following Rab17 knockdown, the relationship between this GTPase and Vamp8 stability is likely to be ...
Vesicle associated membrane proteins are members of the soluble N-ethyl-maleimide-sensitive factor receptor (SNARE) attachment protein family that facilitate the intracellular membrane fusion process involved in neurotransmitter release (Ungar & Hughson, 2003). Cellubrevin, or VAMP-3, is similar to SNARE proteins, synaptobrevin 1 and 2 (VAMP-1 and 2), but can be found in many different tissues such as fibroblasts, adipose cells, insulin-secreting B cells, and supportive brain cells like glial, but not brain neuron cells (Chilcote et al., 1995). However cellubrevin is also a substrate for proteolytic action of tetanus toxin just like VAMP-1 and 2, and suggests similar roles in exocytosis due to the blocking of neurotransmitter release in the presence of tetanus (Chilcote et al., 1995). Cellubrevin has been found to be significant in the docking and vesicle fusion process of secretory granules to the plasma membrane, but few studies in the immunofluorescence localization on subcellular fractions ...
In rodents and humans, alcohol exposure has been shown to predispose the pancreas to cholinergic or viral induction of pancreatitis. We previously developed a rodent model in which exposure to an ethanol (EtOH) diet, followed by carbachol (Cch) stimulation, redirects exocytosis from the apical to the basolateral plasma membrane of acinar cells, resulting in ectopic zymogen enzyme activation and pancreatitis. This redirection of exocytosis involves a soluble NSF attachment receptor (SNARE) complex consisting of syntaxin-4 and synapse-associated protein of 23 kDa (SNAP-23). Here, we investigated the role of the zymogen granule (ZG) SNARE vesicle-associated membrane protein 8 (VAMP8) in mediating basolateral exocytosis. In WT mice, in vitro EtOH exposure or EtOH diet reduced Cch-stimulated amylase release by redirecting apical exocytosis to the basolateral membrane, leading to alcoholic pancreatitis. Further reduction of zymogen secretion, caused by blockade of both apical and basolateral ...
Die integralen Vesikelmembranproteine Synaptophysin und Synaptobrevin interagieren in adulten Neuronen. Zusätzlich bildet Synaptobrevin mit den Plasmamembranproteinen Syntaxin und synaptosome-associated protein 25kDa (SNAP25) den SNAP-Rezeptor (SNARE)-Proteinkomplex, der Voraussetzung für die Fusion zwischen synaptischen Vesikeln und präsynaptischer Membran ist. Mit Synaptophysin interagierendes Synaptobrevin bindet jedoch nicht an den SNARE-Proteinen. Es wird daher vermutet, dass der Synaptophysin/Synaptobrevin-Komplex eine Art Reservepool für Synaptobrevin bei erhöhter neuronaler Aktivität darstellt und die Verfügbarkeit von Synaptobrevin während der Exozytose reguliert. Mit verschiedenen Ansätzen wurde versucht, den auf dem Vesikel befindlichen Komplex genauer zu charakterisieren und in seiner Funktion näher zu beschreiben. Nach Stimulation mit exozytosevermittelnden Substanzen dissoziierte der Synaptophysin/ Synaptobrevin-Komplex, sowohl unter nativen Bedingungen als auch bei ...
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Author summary The seven established Botulinum Neurotoxins serotypes (BoNT/A to G) and the many BoNT subtypes, the causative agents of botulism, are the most poisonous substances known (lethal doses in the low ng/kg range). Due to their toxicological properties, BoNTs are Janus-faced toxins: potent pathogenic factors and potential bioterrorism agents as well as safe and efficacious therapeutics. BoNTs exert their neuroparalytic action by cleaving SNARE proteins, either SNAP-25 or synaptobrevin/VAMP, which mediate neurotransmitter release at the neuromuscular junction; BoNT/C is the only serotype shown to cleave SNAP-25 and syntaxin-1 in vitro. Our study shows for the first time that this parallel cleavage also occurs in vivo. By using mutated toxins reported to be syntaxin-selective, we found that SNAP-25 proteolysis at the neuromuscular junction is the key determinant of BoNT/C lethality as it completely blocks nerve-muscle transmission. Conversely, syntaxin-1 cleavage only attenuates nerve terminal
Figure: Early endosomal components, BEN1 ARF GEF and BEN2/VPS45, are required for repolarization of PIN1-GFP (green) during lateral root organogenesis.. In this study, we have characterized early endosomal trafficking of PIN proteins using two Arabidopsis mutants,ben1 and ben2, which as we had shown previously, are defective in endosomal trafficking as well as pharmacological interference of trafficking at the trans-Golgi network / early endosome. Molecular cloning of the BEN2 gene revealed that the ben2 was a weak allele of the AtVPS45 gene encoding a Sec1/Munc18 family protein which regulates SNARE-dependent membrane fusion. We also found that VPS45/BEN2 resides in the early endocytic route and this localization was abolished by the ben2 mutation. The mutant phenotypes suggested that VPS45/BEN2 is involved in the fusion of endocytic cargoes to the TGN/EE, whereas another TGN/EE-localized ARF,GEF component BEN1,functions in the transport of cargoes from there. Taken together, the results showed ...
Role of the synaptobrevin C terminus in fusion pore formation.: Neurotransmitter release is mediated by the SNARE proteins synaptobrevin II (sybII, also known a
Timmers KI, Clark AE, Omatsu-Kanbe M, Whiteheart SW, Bennett MK, Holman GD and Cushman SW. Experimental Diabetes, Metabolism and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.. The vesicle-associated membrane proteins [VAMPs; vesicle SNAP receptors (v-SNAREs)] present on GLUT4-enriched vesicles prepared from rat adipose cells [Cain, Trimble and Lienhard (1992) J. Biol. Chem. 267, 11681-11684] have been identified as synaptobrevin 2 (VAMP 2) and cellubrevin (VAMP 3) by using isoform-specific antisera. Additional antisera identify syntaxins 2 and 4 as the predominant target membrane SNAP receptors (t-SNAREs) in the plasma membranes (PM), with syntaxin 3 at one-twentieth the level. Syntaxins 2 and 4 are enriched 5-10-fold in PM compared with low-density microsomes (LDM). Insulin treatment results in an 11-fold increase in immunodetectable GLUT4 in PM and smaller (approx. 2-fold) increases in VAMP 2 and ...
Toxicity of human alpha-synuclein when expressed in simple organisms can be suppressed by overexpression of endoplasmic reticulum (ER)-to-Golgi transport machinery, suggesting that inhibition of constitutive secretion represents a fundamental cause of the toxicity. Whether similar inhibition in mammals represents a cause of familial Parkinsons disease has not been established. We tested elements of this hypothesis by expressing human alpha-synuclein in mammalian kidney and neuroendocrine cells and assessing ER-to-Golgi transport. Overexpression of wild type or the familial disease-associated A53T mutant alpha-synuclein delayed transport by up to 50%; however, A53T inhibited more potently. The secretory delay occurred at low expression levels and was not accompanied by insoluble alpha-synuclein aggregates or mistargeting of transport machinery, suggesting a direct action of soluble alpha-synuclein on trafficking proteins. Co-overexpression of ER/Golgi arginine soluble N-ethylmaleimide-sensitive factor
The SNARE fusion complex, fusing neurotransmitter vesicles with the presynaptic membrane. Ca2+ acts on the synaptic vesicle synaptotagmin1 (synaptotagmin I; SytI, Syt1, SSVP65, SYT) to trigger rapid exocytosis (Chapman, 2008). Syt1 is a major Ca2+ sensor for fast neurotransmitter release. It contains tandem Ca2+-binding C2 domains (C2AB), a single transmembrane α-helix and a highly charged 60-residue- long linker in between. The linker region of Syt1 is essential for its two signature functions: Ca2+-independent vesicle docking and Ca2+-dependent fusion pore opening. The linker contains the basic-amino acid-rich N-terminal region and the acidic amino acid-rich C-terminal region (Lai et al. 2013). The intrinsically disordered region between Syt Is transmembrane helix and the first C2 domain interats with vesicular lipids and modulates Ca2+ binding to C2 (Fealey et al. 2016). t-SNARE and v-SNARE interact in their C-terminal TMSs to promote pore opening (Wu et al. 2016). Both sides of a ...
The yeast Saccharomyces cerevisiae is a widely used platform for the production of heterologous proteins of medical or industrial interest. However, heterologous protein productivity is often restricted due to the limitations of the host strain. In the protein secretory pathway, the protein trafficking between different organelles is catalyzed by the soluble NSF (N-ethylmaleimide-sensitive factor) receptor (SNARE) complex and regulated by the Secl/Munc18 (SM) proteins. In this study, we report that over-expression of the SM protein encoding genes SEC1 and SLY1, improves the protein secretion in S. cerevisiae. Engineering Sec1p, the SM protein that is involved in vesicle trafficking from Golgi to cell membrane, improves the secretion of heterologous proteins human insulin precursor and alpha-amylase, and also the secretion of an endogenous protein invertase. Enhancing Sly1p, the SM protein regulating the vesicle fusion from endoplasmic reticulum (ER) to Golgi, increases alpha-amylase production only. Our
The plant Golgi apparatus is polydisperse and COPII fluorescence localizes to the interface between the ER and the overlying Golgi stack rather than the surface of the ER. Per definition, ER exit sites (ERES) are COPII vesiculation events at the surface of the ER and are only visualizable in the electron microscope through cryofixation techniques. Nevertheless, ERES is always associated with Golgi stacks and both move together. We have asked whether the domain of the ER where retrograde COPI vesicles fuse, i.e. ER import sites, (ERIS), is also coupled to Golgi stack motility and therefore spatially associated with ERES? As ERIS markers we have investigated ER-located SNAREs and tethering factors. We screened several SNAREs (SYP81, the SYP7 family, and USE1) to find a SNARE whose overexpression did not disrupt ER-Golgi traffic and which gave rise to discrete fluorescent punctae when expressed with an XFP tag. Only the Qc SNARE SYP72 fulfilled these criteria, and, based on quantitative protein transport
Syntaxin-binding protein 3 is a protein that in humans is encoded by the STXBP3 gene. Syntaxin binding protein 3 has been shown to interact with STX2 and STX4. GRCh38: Ensembl release 89: ENSG00000116266 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000027882 - Ensembl, May 2017 "Human PubMed Reference:". "Mouse PubMed Reference:". Reed GL, Houng AK, Fitzgerald ML (May 1999). "Human platelets contain SNARE proteins and a Sec1p homologue that interacts with syntaxin 4 and is phosphorylated after thrombin activation: implications for platelet secretion". Blood. 93 (8): 2617-26. PMID 10194441. "Entrez Gene: STXBP3 syntaxin binding protein 3". Schraw, Todd D; Lemons Paula P; Dean William L; Whiteheart Sidney W (Aug 2003). "A role for Sec1/Munc18 proteins in platelet exocytosis". Biochem. J. England. 374 (Pt 1): 207-17. doi:10.1042/BJ20030610. ISSN 0264-6021. PMC 1223584 . PMID 12773094. Widberg, Charlotte H; Bryant Nia J; Girotti Milena; Rea Shane; James David E (Sep 2003). "Tomosyn ...
Involved in the targeting and/or fusion of transport vesicles to their target membrane. Modulates the gating characteristics of the delayed rectifier voltage-dependent potassium channel KCNB1.
Stainless steel tonsil snare with hand and finger lock. Apparatus is constructed of three pieces. Central piece contains a large opening for a four-fingered grip, with a guide sleeve for a thin metal rod which is moved back and forth in the sleeve by a third piece, a thumb grip and lever which moves the metal rod. The thumb grip and lever are attached to the finger grip with a small screw hinge, and has a curved arm to provide forward and reverse movement of the rod. The rod has to small openings at the distal end to provide for the attachment of a wire ...
China Endoscopic Accessories supplier, Disposable Biopsy Forceps, Polypectomy Snare Manufacturers/ Suppliers - Changzhou JIUHONG Medical Instrument Co., Ltd.
The ever-smart Shack News has pointed out The Rabbit Snare, a good site translating lengthy Japanese-language interviews with important game designers and random game crazies, and of which we had not heard until now!. For starters, theres Secrets Of The Katamari, translating an old Dengeki Online interview with Keita Takahashi in fine style, explaining of Katamari Damacy: "Specifically, I think it was going to be an action game with some driving elements in it. I thought up the King and the Prince as part of that games back-story. And, well, it was rejected, of course…(laughs). Itd always seemed like a waste of a good idea to me, so when we started development on Katamari Damacy, I thought it might be possible to use it this time around.". Oh yeah, and he also translated the voiceover/text for the Ultimate Ghosts N Goblins promo movie, which would have been really useful when we were watching it: "I was taking it easy, you know... I left Demonville, where I had fought for so long, and was ...
Previous work suggests that interactions of syntaxin with calcium channels are functionally important in active zones (Catterall, 1999; Mochida, 2000; Teng et al., 2001; Atlas, 2001). Presynaptic Ca2+ channels bind syntaxin, and this interaction may serve to localize the source for Ca2+ ions near the Ca2+ sensor, increasing the efficiency of transmitter release (Mochida et al., 1996; Rettig et al., 1997). Syntaxin also increases calcium channel inactivation, potentially reducing transmitter release, and this inhibitory effect is relieved by other SNARE proteins and synaptotagmin (Bezprozvanny et al., 1995; Smirnova et al., 1995; Wiser et al., 1996; Sutton et al., 1999; Zhong et al., 1999; Bergsman and Tsien, 2000; Degtiar et al., 2000; Jarvis et al., 2000, 2002; Zamponi, 2003). How would these apparently opposing actions affect synaptic transmission in vivo? At control synapses, some Ca2+ channels in the active zone are associated with a docked vesicle. At sites at which vesicles are docked, we ...
ABSTRACT: The glucose transporter GLUT4 plays central roles in maintaining blood glucose homeostasis. Under basal conditions, GLUT4 is sequestered in intracellular vesicles in adipose and skeletal muscle cells. Upon insulin stimulation, GLUT4-containing vesicles fuse with the plasma membrane, relocating GLUT4 to the cell surface. Once on the cell surface, GLUT4 facilitates the uptake of excess blood glucose into the cell for disposal, thereby maintaining the blood glucose homeostasis. Imbalances in GLUT4 exocytosis result in insulin resistance and type 2 diabetes. GLUT4 vesicle fusion requires SNAREs as the core machinery, and a large group of regulatory factors. It remains unclear how SNAREs act in concert with the regulatory factors to mediate and regulate GLUT4 vesicle fusion. We are addressing the problem from a novel angle by reconstituting GLUT4 vesicle fusion in vitro using purified components, and then validating our findings in adipocytes. In defined fusion systems, SNAREs and ...
Opens the Highlight Feature Bar and highlights feature annotations from the FEATURES table of the record. The Highlight Feature Bar can be used to navigate to and highlight other features and provides links to display the highlighted region separately. Links in the FEATURES table will also highlight the corresponding region of the sequence. More... ...
Research proven purified goat polyclonal VAMP-1 antibody. Involved in neurotransmission including synapse vesicle transport and release. VAMPs also appear to be significantly lowered in Alzheimers Disease. Designed for immunohistochemistry, western blotting, Direct ELISA and related applications. IHC and WB images in product description.
Adaptor Proteins Signal Transducing metabolism Animals Caenorhabditis elegans Proteins metabolism Calcium/metabolism Cell Membrane metabolism ultrastructure Drosophila Proteins metabolism Exocytosis physiology Membrane Fusion physiology Membrane Proteins metabolism Munc18 Proteins Nerve Tissue Proteins genetics metabolism Phosphoproteins metabolism Qa-SNARE Proteins SNARE Proteins Synaptic Transmission physiology Synaptic Vesicles metabolism ultrastructure Vesicular Transport Proteins genetics metabolism Yeasts/physiology rab GTP-Binding Proteins ...
The seven antigenically distinct serotypes (A to G) of botulinum neurotoxin (BoNT) are responsible for the deadly disease botulism. BoNT serotype A (BoNT/A) exerts its lethal action by cleaving the SNARE protein SNAP-25, leading to inhibition of neurotransmitter release, flaccid paralysis and autonomic dysfunction. BoNTs are dichain proteins: the heavy chain is responsible for neurospecific binding, internalization and translocation, and the light chain is responsible for substrate cleavage. Because of their extreme toxicity and prior history of weaponization, the BoNTs are considered to be potential bioterrorism agents. No post-symptomatic therapeutic interventions are available for BoNT intoxication other than critical care; therefore it is imperative to develop specific antidotes against this neurotoxin. To this end, a cyclic peptide inhibitor (CPI-1) was synthesized and found to inhibit BoNT/A light chain (Balc) with high affinity. When tested in a cell-free Förster resonance excitation ...
To identify the causative mutation in au18, we performed next-generation sequencing followed by SNP mapping using the MegaMapper analysis pipeline.30 Whole-genome sequencing of au18 mutants generated ∼11× average coverage of the zebrafish genome. MegaMapper analysis identified a 6-Mb window on chromosome 12 as the likely location of the causative mutation. Within this window, a C-to-A transversion mutation at nucleotide 893 (C893T) of the nsfb coding sequence was predicted to be the mutation underlying the au18 phenotype. This mutation is predicted to cause a premature stop codon at amino acid 297, truncating nsfb by 60% (S297X). Complementary DNA sequencing confirmed the presence of this mutation in homozygous au18 mutant embryos and its absence in wild-type embryos (Fig. 3A). Nsfb contains three major domains: an N-terminal binding domain required for its association with SNAP-complex proteins and two ATPase domains, D1 and D2 (Fig. 3A). The first ATPase domain is required for overall ...
Botulinum neurotoxin A (BoNT/A) induces muscle paralysis by enzymatically cleaving the presynaptic SNARE protein SNAP-25, which results in lasting inhibition of acetylcholine release at the neuromuscular junction. A rapid and sensitive in vitro assay for BoNT/A is required to replace the mouse lethality assay (LD50) in current use. We have developed a fully automated sensor to assay the endoprotease activity of BoNT/A. We produced monoclonal antibodies (mAbs) that recognize SNAP-25 neo-epitopes specifically generated by BoNT/A action. Recombinant SNAP-25 was coupled to the sensor surface of a surface plasmon resonance (SPR) system and samples containing BoNT/A were injected over the substrate sensor. Online substrate cleavage was monitored by measuring binding of mAb10F12 to a SNAP-25 neo-epitope. The SNAP-25-chip assay was toxin serotype-specific and detected 55 fM BoNT/A (1 LD50/ml) in 5 min and 0.4 fM (0.01 LD50/ml) in 5h. Time-course and dose-response curves were linear, yielding a limit of ...
The controlled release of neurotransmitters is central to information processing in the nervous system, and is altered in many psychiatric and neurological disorders. The minimal protein machinery for this process (the clamp/activator Complexin, the calcium sensor Synaptotagmin, and the synaptic SNAREs VAMP2, Syntaxin1 and SNAP25) has been known for a while. Yet it is still not understood how the entry of calcium at nerve endings triggers the synchronous release of neurotransmitters that physiology requires.. Recent structural and biochemical studies done in our lab has suggested a novel and detailed structural /biochemical working model to explain the synchronous release of neurotransmitters occurs (shown on the right).. ...
Toxic proteins produced from the species CLOSTRIDIUM BOTULINUM. The toxins are synthesized as a single peptide chain which is processed into a mature protein consisting of a heavy chain and light chain joined via a disulfide bond. The botulinum toxin light chain is a zinc-dependent protease which is released from the heavy chain upon ENDOCYTOSIS into PRESYNAPTIC NERVE ENDINGS. Once inside the cell the botulinum toxin light chain cleaves specific SNARE proteins which are essential for secretion of ACETYLCHOLINE by SYNAPTIC VESICLES. This inhibition of acetylcholine release results in muscular PARALYSIS ...
induction of synaptic vesicle exocytosis by positive regulation of presynaptic cytosolic calcium ion concentration - Ontology Report - Chinchilla Research Resource Database
We wjndows that the presence of windowa C-terminal 9xHA tag might minimally interfere with the generation of the unusually large Rab7-positive alpha vacuoles in nephrocytes. Will the DNS mask my location or will only the VPN do this. If you want an IP address from the UK, select the data centre from Londonв when creating your Digital Ocean VPS, as shown in the image below. It is imaging software for windows server 2008 r2 in the biological process described with: neuron projection morphogenesis; intracellular protein transport; regulation of SNARE complex assembly; regulation of Notch signaling pathway; vesicle-mediated transport; autophagosome maturation; cellular response imaging software for windows server 2008 r2 starvation. He is working in PURNAYOO as a Resident medical officer since 2009. vpsMachine Quality openvz hosting platform with a large choice of customer OS templates. The price of website hosting depends on the plan that you choose. Serveer start by introducing you to the ...
0007] The pull method is similar in some respects to the above-described push method, the pull method differing from the push method in that, after the cannula is snared and the needle is removed therefrom, a looped first end of a suture (also known in the art as a "pullwire") is inserted through the cannula and into the stomach where it is grasped by the snare, the second end of the suture remaining external to the patient. The endoscope and the snare are then withdrawn from the mouth of the patient to deliver the first end of the suture. The first end of the suture is then coupled to the leading end of a pull-type catheter implanting assembly, the pull-type catheter implanting assembly typically comprising a gastrostomy feeding tube having an internal bolster integrally formed at its trailing end and a plastic fitting attached to its leading end. The plastic fitting typically has a barbed rear portion mounted within the leading end of the feeding tube and a conical front portion that serves as ...
VAMP1 - VAMP1 (untagged)-Human vesicle-associated membrane protein 1 (synaptobrevin 1) (VAMP1), transcript variant 2 available for purchase from OriGene - Your Gene Company.
Forty-eight hours posttransfection, supernatants were collected for viral infectivity assays or centrifuged through a 20 sucrose cushion. Resellers accounts may vary tremendously in size: they may have their own virtual dedicated server to a colocated server. Crystal structure of the hexamerization domain of N-ethylmaleimide-sensitive fusion protein. Ultrafast Branded Dell and HP Servers for your mission rwtrieve applications, Redundant TIER II Network and N1 Cooling, Power generator for 100 Uptime. As such, it wasnt covered by the brilliant AX-HLE Rewrite in 2013. Great reviews on web hosting. The percentages of cells in different phases were detected by flow cytometry. All data is stored on the companys UK-based (Maidenhead) servers. The ultrasound scan unit is functioning under the department is one of the mssqlserver login failed contributions of werver department to the hospital, the students and the community as a whole. RNA expression overview shows RNA-data from three different ...
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Adrenomedullary chromaffin cells have been used as an excellent experimental model to study the exocytosis and therefore the molecular mechanisms of neurotransmission. It is now clear that the proteins involved in the processes of vesicle docking, membrane fusion and neurotransmitter release are common to many cellular systems (SNARE hypothesis). Our research interest is focused in two different aspects of the molecular mechanisms of neurotransmission: Implication of molecular motors such myosin-actin in vesicle transport during neurosecretion and the determination of essential aminoacids of synaptobrevin or SNAP-25 implicated in the process of membrane fusion. Experimental approaches involve strategies using antibodies, sequence peptide design and protein overexpression that demonstrate the participation of specific protein domains in exocytosis. In addition, the role of these proteins on the secretory stages have been studied using amperometry, technique that resolves single fusion events ...
Neuronal cell death seems to be correlated with age of onset and duration of the disease in most NCLs [19]. In AD-ANCL there is a remarkable neuronal depletion in the cortex of the frontal, parietal and temporal lobes of the AD-ANCL terminal cases [5]. Here, we found minimal to no evidence of neuronal loss or cortex atrophy in a clinically early-stage patient with AD-ANCL in the examined areas.. Microgliosis and astrogliosis seems to be an early event, possibly even occurring before neuronal degeneration in several NLCs [19, 20] including adult forms [5], and remains remarkable in very advanced stages of neurodegeneration in the cerebral cortex [5, 19]. Here, we found microglial and astroglial activation in isolated areas surrounding the swollen neurons in the cortex of an early-stage AD-ANCL patient.. Here, we report that terminal AD-ANCL patients exhibit reductions in presynaptic proteins that form the SNARE complex including SNAP-25, VAMP2 and STX1 (Fig. 6a, b). A similar reduction in SNAP-25 ...
SNARe™ Simple Nucleic Acid Recovery DNA Purification System. SNARe™ Plant Genomic DNA Purification System offers a rapid, cost-effective method for isolating DNA. The procedure does not require the use of organic solvents and is adaptable to different plant species. DNA Separation Particles, supplied in the system, are a suspension of superparamagnetic particles that bind double-stranded DNA. 了解更多 ...
Yesterday saw the unveiling of "Never Work For Free," the first pre-release track from Tennis upcoming, highly-anticipated album, Ritual In Repeat. Explore new territories and swim into the salty waters of what sounds like analogue synthesizers, alternative guitar tunings and self-reflection. This Denver couple, Alaina Moore and Patrick Riley, never disappoint - and once again, their melodies and lines are newly filled with an invigorating beauty and brilliance.. ...
We all have dinner at Tabule. There is white wine and spectacular hummus, labne and tawuk. Later, ryan, Neil, Emily, Gennie, angela rawlings, Jenny Sampirisi, Aaron and I all wind up at Gennies apartment. We sing, listen to music videos, drink, and read tea leaves. Angela has notes form our performances, excellent and difficult questions. We try to name Jennys book and actually find the tabs to My Belruel. Jenny, angela, ryan and Aaron eventually leave before the subways stop running and after Neil goes to bed Gennie, Emily and I lay on the futon and talk, There is power in having us together again. Emily stays the night and it feels so good to have all the pieces of myself reassembled for just a few hours ...
The Munc13 proteins are the key mediators of synaptic vesicle priming, an essential step in Ca2+-regulated neurotransmitter release that renders docked vesicles fusion-competent prior to exocytosis. They have emerged as important regulators of adaptive synaptic mechanisms such as presynaptic short-term plasticity, a process by which the release of neurotransmitter is dynamically adapted to a changing demand. Indeed, Munc13-1 and ubMunc13-2 contain a conserved calmodulin (CaM) binding site and the Ca2+-dependent interaction of these Munc13 isoforms with CaM constitutes a molecular mechanism that transduces residual Ca2+ signaling to the synaptic exocytotic machinery. This study aimed to (i) establish whether such regulation through CaM exists in the other Munc13 isoforms, bMunc13-2 and Munc13-3, and (ii) provide structural insights into the Munc13-CaM interaction. Bioinformatic tools were used to identify potential CaM recognition motifs in the non-conserved sequences of bMunc13-2 and Munc13-3. ...
immune Uncategorized Ciproxifan, FNDC3A Autophagy an important catabolic pathway implicated in a wide spectrum of individual diseases starts by forming twice membrane autophagosomes that engulf cytosolic cargo and ends by fusing autophagosomes with lysosomes for degradation1 2 Membrane fusion activity is necessary for early biogenesis of autophagosomes and later degradation in Ciproxifan lysosomes3-7. mutant6 still destined to ATG14 (Fig. 1a). Recombinant ATG14 destined to STX17 by itself as well as the STX17-SNAP29 binary t-SNARE complicated but not towards the STX17-SNAP29-VAMP8 ternary complicated (Fig. 1b) recommending that ATG14 binds before development of pull-down assay (Fig. 3e). ATG14 homo-oligomerization is vital because of its relationship with autophagic SNAREs thus. The relationship between these ATG14 HOD mutants and beclin 1 continued to be intact (Prolonged Data Fig. 6a). Within a reconstituted program purified and may be the ten-frame-averaged strength worth of acceptor dye ...
What is the molecular basis of cell matching? The data above are consistent with matching being based on just two sets of molecular interactions, one allowing A compartment cells to recognise one another and the other performing the same function for P compartment cells. An obvious possibility is that the molecules that mediate cell matching during DC are the same as those that maintain the integrity of these compartments throughout the epithelium. Alternatively, there could be a different set of recognition molecules present exclusively at the leading edge to mediate cell-cell matching. Filopodia are also observed during the healing of wounds in the ventral epithelium and we reasoned that these wound filopodia should exhibit matching behaviour if the molecules that mediate matching are present throughout the epithelium (Wood et al., 2002). Laser wounds were made to the ventral epithelium across en stripes such that the wound edge consisted of both en-RFP-Moesin and ptc-GFP-Moesin cells. On ...
Regulated exocytosis is a stimulus-dependent membrane fusion event of fundamental importance to a range of physiological processes. The membrane fusion reaction...
Author: Ngatchou, A. N. et al.; Genre: Journal Article; Published in Print: 2010-10-26; Title: Role of the synaptobrevin C terminus in fusion pore formation.
Describes how to procure food, store food, and cook food in a survival situation. Also how to hunt for game with primitive methods, traps, and snares.
And a servant of the Lord must not quarrel but be gentle to all, able to teach, patient, in humility correcting those who are in opposition, if God perhaps will grant them repentance, so that they may know the truth, and that they may come to their senses and escape the snare of the devil, having been taken captive by him to do his will." (2 Timothy 2:24-26 ...
Extracellular signal-regulated kinases(ERKs), belonging to the family of mitogen-activated protein kinases (MAPKs), are cytoplasmic and nuclear serine/threonine kinases involved in the signal transduction of several extracellular effectors. Recent evidence indicates the presence of p21 Ras and the phosphorylation of ERK1 and ERK2, suggesting the occurrence of the Ras/ERK cascade in mammalian spermatozoa. The present article describes the biological role of ERK during the acrosome reaction of human spermatozoa on stimulation with zona pellucida (ZP). The mitogen-activated protein-kinase inhibitor PD098059 was used as a pharmacological tool to study the involvement of extracellular signal-regulated kinases in the induction of the acrosome reaction in human spermatozoa. This compound significantly inhibited the acrosome reaction induced by both ZP and the calcium ionophore A23187. These results suggest that ERKs are involved in the signal trans-duction pathway through which ZP stimulation works ...
Several recent studies have indicated that radiofrequency electromagnetic fields (RFEMF) have an adverse effect on human sperm quality, which could translate to an effect on fertilization potential. The present study evaluated the effect of RF-EMF on spermspecific characteristics in order to assess the fertilizing competence of sperm. Highly motile human spermatozoa, were exposed for one hour to 900 MHz mobile phone radiation at a specific absorption rate (SAR) of 2.0 W/kg and examined at various times after exposure. The acrosome reaction was evaluated using flow cytometry. The radiation did not affect sperm propensity for the acrosome reaction. Morphometric parameters were assessed by computer assisted sperm analysis (CASA). Significant reduction in sperm head area (9.2 ± 0.7 μm2 vs. 18.8 ± 1.4 μm2) and acrosome percentage of the head area (21.5 ± 4% vs. 35.5 ± 11.4%) were reported among exposed sperm compared with unexposed controls. Sperm-zona binding was assessed directly after ...
Principal Investigator:ISHIKAWA Hiromichi, Project Period (FY):1995 - 1996, Research Category:Grant-in-Aid for Scientific Research (B), Section:一般, Research Field:Urology
This study was designed to test the effects of pentoxifylline and progesterone upon capacitation of fresh human spermatozoa. Capacitation and acrosomal integrity were assessed using the fluorescent probe chlortetracycline on spermatozoa co-stained with a supravital fluorescent dye, Hoechst 33258. Hyperactivated motility was measured using computer-assisted movement analysis. After exposure to pentoxifylline (1 mg/ml; 30 min), the fluorescent B pattern, characteristic of capacitated, acrosome-intact cells, increased significantly (P | 0.01), though no increase in AR pattern, characteristic of acrosome-reacted cells, was detected. There was a significant increase in hyperactive motility (P | 0.001). Exposure to progesterone (1 microgram/ml; 60 min) resulted in a significant increase in B pattern (P | 0.05) and AR pattern (P | 0.005), though no effect on the expression of hyperactivation was detected. No effect upon hyperactivation was detected on exposure of fresh or cryopreserved spermatozoa to a
Looking for online definition of acrosome malformation of spermatozoa in the Medical Dictionary? acrosome malformation of spermatozoa explanation free. What is acrosome malformation of spermatozoa? Meaning of acrosome malformation of spermatozoa medical term. What does acrosome malformation of spermatozoa mean?
In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS) plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC). Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam) and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P) pattern and percentages of ARC and non-viable cells (NVC). Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting
During mammalian fertilization, the exposure of the inner acrosomal membrane (IAM) after acrosomal exocytosis is essential for the secondary binding between sperm and zona pellucida (ZP) of the oocyte, a prerequisite for sperm penetration through the ZP. The identification of the sperm protein(s) responsible for secondary binding has posed a challenge for researchers. We were able to isolate a sperm head fraction in which the IAM was exposed. Attached to the IAM was an electon dense layer, which we termed the IAM extracellular coat (IAMC). The IAMC was also observable in acrosome reacted sperm. High salt extraction removed the IAMC including a prominent 38 kDa polypeptide, referred to as IAM38. Antibodies raised against IAM38 confirmed its presence in the IAMC of intact, sonicated, and acrosome-reacted sperm. Sequencing of IAM38 revealed it as the ortholog of porcine SP38, a protein that was found to bind specifically to ZP2 but whose intra-acrosomal location was not known. We showed that IAM38 ...
Incubation of boar spermatozoa in a capacitation medium with oligomycin A, a specific inhibitor of the F0 component of the mitochondrial ATP synthase, induced an immediate and almost complete immobilisation of cells. Oligomycin A also inhibited the ability of spermatozoa to achieve feasible in vitro capacitation (IVC), as measured through IVC-compatible changes in motility patterns, tyrosine phosphorylation levels of the acrosomal p32 protein, membrane fluidity and the ability of spermatozoa to achieve subsequent, progesterone-induced in vitro acrosome exocytosis (IVAE). Both inhibitory effects were caused without changes in the rhythm of O2 consumption, intracellular ATP levels or mitochondrial membrane potential (MMP). IVAE was accompanied by a fast and intense peak in O2 consumption and ATP levels in control spermatozoa. Oligomycin A also inhibited progesterone-induced IVAE as well as the concomitant peaks of O2 consumption and ATP levels. The effect of oligomycin on IVAE was also accompanied by
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Shop Sperm acrosome membrane-associated protein ELISA Kit, Recombinant Protein and Sperm acrosome membrane-associated protein Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
Looking for acrosome? Find out information about acrosome. The anterior, crescent-shaped body of spermatozoon, formed from Golgi material of the spermatid. Also known as perforatorium Explanation of acrosome
Capacitation encompasses the molecular changes sperm undergo to fertilize an oocyte, some of which are postulated to occur via a cAMP-PRKACA (protein kinase A)-mediated pathway. Due to the recent discovery of cAMP-activated guanine nucleotide exchange factors RAPGEF3 and RAPGEF4, we sought to investigate the separate roles of PRKACA and RAPGEF3/RAPGEF4 in modulating capacitation and acrosomal exocytosis. Indirect immunofluorescence localized RAPGEF3 to the acrosome and subacrosomal ring and RAPGEF4 to the midpiece in equine sperm. Addition of the RAPGEF3/RAPGEF4-specific cAMP analogue 8-(p-chlorophenylthio)-2-O-methyladenosine-3,5-cyclic monophosphate (8pCPT) to sperm incubated under both noncapacitating and capacitating conditions had no effect on protein tyrosine phosphorylation, thus supporting a PRKACA-mediated event. Conversely, activation of RAPGEF3/RAPGEF4 with 8pCPT induced acrosomal exocytosis in capacitated equine sperm at rates (34%) similar (P > 0.05) to those obtained in ...
CD52 is a glycosylphosphatidylinositol (GPI)-anchored antigen expressed on lymphocytes and in epididymal epithelial cells. CD52 is also known as maturation-associated sperm antigen but its function is unknown. We therefore generated Cd52 disrupted mice. The resulting Cd52 null mice were healthy, even though Cd52 is expressed on cells of the immune system. We then examined a possible role for CD52 in reproduction. Sperm from Cd52-deficient males were investigated and the viability, motility, morphology, and incidence of spontaneous acrosome reactions were found to be all similar to values for wild-type sperm. In in vitro fertilization system, the sperm showed normal fertilizing ability. As CD52 was found to be transferred onto sperm only after they had migrated into the vas deferens, we examined the behavior of sperm from Cd52-deficient mice in vivo. The mice mated naturally and we observed that a normal number of sperm passed through the uterotubal junction, known to the crucial hurdle for ...
1. Daneva T, Zierhut B, Gartner W, & Wagner L. Fine tuning of insulin transcription by secretagogin variants. Comp. Rend. Bulg. Acad. Sci. 8: 983-988 (2005). ISSN: 1310-1331, IF-0.204 2. Vangelov I, Dineva J, Nikolov G, Genov M, Ivanova M. Anti-granulosa antibodies (AGA) in follicular fluids and their impact to controlled ovarian hyperstimulation and on the fertilization rate. Comp. Rend. Bulg. Acad. Sci. 59: 1191-96 (2006). ISSN: 1310-1331, IF-0.204. 3. Dineva J, Vangelov I, Nikolov G, Gulenova D, Ivanova M. Apoptosis of human Granulosaluteinized (GLCs) and Cumulus cells(CCs) as a possible indicator for IVF outcome. Comp. Rend. Bulg. Acad., 59: 781-784 (2006) ISSN: 1310-1331, IF-0.204. 4. Mollova M, Martinova Y. Immunocytochemical localization of antigen involved in sperm-zona pellucida interaction. Acta Morphol. et Antropol., 13, 98-101 (2006). ISSN 0861-0509. 5. Martinova Y, Mollova M, Petrov M, Rashev P, Ivanova M. TEM and SEM characteristics and lectin binding distribution of cat zona ...
Please distribute: CLARIFICATION: OPEN TO USA AND NON-USA CITIZENS/RESIDENTS POSTDOCTORAL POSITIONS IN MAMMALIAN FERTILIZATION NIH-funded postdoctoral positions are available immediately to study the biochemistry of mammalian gamete recognition. Recent studies show that sperm surface galactosyltransferase is a receptor for ZP3 oligosaccharides in the egg zona pellucida (,fontfamily,,param,Geneva,/param,Nature, 1992, 357:589-593,/fontfamily,). Aggregation of galactosyltransferase by multivalent ZP3 oligosaccharides leads to activation of a heterotrimeric G-protein cascade, which culminates in the acrosome reaction (Science, 1995,,fontfamily,,param,Geneva,/param, 269:1718-1721,/fontfamily,). Although galactosyltransferase-null sperm do not bind ZP3 oligosaccharides nor undergo an acrosome reaction, they still bind to the zona pellucida (Development, 1997,,fontfamily,,param,Geneva,/param, 124:4121-4131,/fontfamily,). This suggests that galactosyltransferase cooperates with other sperm surface ...
REFERENCES. Agca Y, Critser JK. 2002. Cryopreservation of spermatozoa in assisted reproduction. Semin Reprod Med 20, 15-23. [ Links ] Ahammad MU, Nishino C, Tatemoto H, Okura N, Okamoto S, et al. 2013. Acrosome reaction of fowl sperm: Evidence for shedding of the acrosomal cap in intact form to release acrosome enzyme. Poult Sci 92,798-803. [ Links ] Arenas E, Cambrón RA, Ambriz GE. 2010. Bases fisiológicas de la capacitación y de la reacción acrosomal del espermatozoide, División de Ciencias Biológicas y de la Salud. Universidad Autónoma Metropolitana-Iztapalapa. Contactos 78, 5-11. [ Links ] Ashizawa K, Wishart G, Katayama S, Takano D, Maeda M, et al. 2006. Effects of calpain and Rho-kinase inhibitors on the acrosome reaction and motility of fowl spermatozoa in vitroReproduction 131, 71-79. [ Links ] Blanco JM, Long JA, Gee G, Donoghue AM, Wildt DE. 2008. Osmotic tolerance of avian spermatozoa: influence of time, temperature, cryoprotectant and membrane ion pump function on sperm ...
Acrosome Definition - The acrosome is a cap that covers the head of the sperm. The acrosome facilitates the acrosomal reaction, which occurs when the...
In this study, we addressed several questions concerning the effect of estrogens on boar sperm in vitro. Although several previous studies have reported on the effects of estrogen in mature spermatozoa among different species, there are some contradictory results in this field. Therefore we employed multiple evaluation techniques to complexly analyze the effect of estrogen on boar sperm in vitro. The obtained results from each method might be useful whilst searching for specific mechanisms, which mediate the estrogen effect in mammalian sperm.. The first experiment addressed the question of whether strong, naturally occurring estrogen (E2) has a significant impact on the boar sperm capacitation progress at different capacitation times. Sperm were capacitated in vitro in the presence of 1 μM E2 or ethanol (control). We found out that 1 μM E2 has a procapacitation effect on the boar sperm in vitro. Furthermore, we demonstrated the non-identical effect of E2 on capacitation at different times of ...
Beltran,C. Trevino,C.L. Mata-Martinez,E. Chavez,J.C. Sanchez-Cardenas,C. Baker,M. Darszon,A. 2016. Role of Ion Channels in the Sperm Acrosome Reaction en: Buffone,M.G. Sperm Acrosome Biogenesis and Function During Fertilization. Springer International Publishing Switzerland. pags. 35-69 Reyes,J.G. Sanchez-Cardenas,C. Acevedo-Castillo,W. Leyton,P. Lopez-Gonzalez,I. Felix,R. Gandini,M.A. Trevino,M.B. Trevino,C.L. 2014. Maitotoxin: An Enigmatic Toxic Molecule with Useful Applications in the Biomedical Sciences en: Botana,L.M. Seafood and Freshwater Toxins. Pharmacology, Physiology, and Detection. Boca Raton. CRC Press. pags. 677-694 * Indica publicación con otra institución de adscripción. ...
Comparison of Motility, Acrosome, Viability and ATP of Boar Sperm with or without Cold Shock Resistance in Liquid Semen at 17℃ and 4℃, and Frozen-thawed Semen - Boar;Liquid Semen;Motility;Acrosome;ATP;
Sea urchin and human sperm contain receptors for neurotransmitters and psychoactive drugs, including cannabinoid receptors (CNRs). Anandamide, arachidonoylethanolamide (AEA), is a lipid-signal molecule that is an endogenous agonist for CNRs. AEA is enyzmatically released from membrane phospholipids when neurons are stimulated. Retrograde AEA signals from depolarized postsynaptic neurons inhibit neurotransmitter release at synapses in mammalian brain. Analogous processes regulate sperm functions during fertilization in sea urchins. AEA and (-)delta9tetrahydrocannabinol [(-)delta9THC], the major psychoactive constituent of marijuana, inhibit fertilization by blocking acrosomal exocytosis/acrosome reactions (AR) stimulated by egg jelly. The acrosome is a Golgi-derived secretory granule in sperm analogous to synaptic vesicles in neurons. AEA and (-)delta9THC do not block ionophore-induced AR, suggesting that they inhibit AR by modulating signal transduction event(s) before opening of ion channels. ...
Published in: Bioscience Reports, 1984, 4, 71-82.. Abstract:. We show here the presence of an integral, strong RNAase-A-like ribonucleolytic activity in the plasma and outer acrosomal membranes of bovine spermatozoa. A part of this activity is extractable by salt or detergent. ...
The efficiency of in vitro embryo production (IVEP) in buffalo is hampered by the poor cleavage rate. The quality of the frozen semen may affect fertilization efficiency, due to damages of the male gamete that occur following cryopreservation. However, it is not possible to rule out that the process of capacitation, required by spermatozoa to acquire the fertilizing ability, is impaired in the IVF system. Although several agents have been proven to induce sperm capacitation in vitro, heparin is still the most efficient method in most of the domestic species. The aim of the study was to evaluate the efficiency of buffalo estrus serum (BES) and follicular fluid (FF) to induce buffalo sperm capacitation in vitro, indirectly assessed by estimating the capability of spermatozoa to acrosome react. Frozen semen from a bull previously tested for IVF, thawed at 37°C for 40 s in water, was treated by swim-up in order to select only the motile population. Spermatozoa (n = 1546) were assessed immediately ...
Abstract During mammalian fertilization, spermatozoa must undergo capacitation and the acrosome reaction. These processes of sperm function are critically associated with various m..
Results: Plasma membrane (p< 0.001) and acrosome integrity (p< 0.05) of the spermatozoa were significantly reduced in sodium arsenite group compared to the control. In silymarin + sodium arsenite group, silymarin was able to significantly (p< 0.001) ameliorate the adverse effects of sodium arsenite on these sperm parameters compared to sodium arsenite group. The incubation of sperm for 180 min (control group) showed a significant (p< 0.001) decrease in acrosome integrity compared to the spermatozoa at 0 hour. The application of silymarin alone for 180 min could also significantly (p< 0.05) increase sperm acrosome integrity compared to the control ...
... Reproduction and Development Pregnancy Prevention • Contraceptives (birth control methods) • Abstinence • Total abstinence • Abstinence during periods of female fertility • Interventional methods • • • • Barriers Surgery Blocking implantation Hormone treatments to reduce gamete production Pregnancy Prevention Table 26-5 Fertilization • Sperm capacitation occurs in vagina • Sperm swim "upstream" • Sperm reach oocyte in Fallopian tube • Acrosomal reaction  digestive enzymes • Zona pellucida and cell junctions dissolve • Membranes fuse and sperm nucleu enters • Cortical reaction blocks polyspermy • Nuclear fusion creates a diploid cell • 1 sperm + 1 oocyte  1 zygote Fertilization Figure 26-16a Acrosome Reaction Allows Sperm to Reach Egg Figure 26-16b Sperm and Egg Fuse to Form a Zygote First polar body Egg Sperm nucleus Sperm and egg plasma membranes fuse. Sperm nucleus moves into cytoplasm of egg. Figure 26-17 (1 of 4, 2 of 4) Oocyte Completes ...
Sexual reproduction to perpetuate a given species occurs through fertilization, during which a diploid zygote is formed to produce a genetically distinct individual. To this end, the haploid sperm and haploid egg must collide to allow entry of the sperm head delivering the male chromatin into the egg cytoplasm. Both the male and female gametes undergo regulated exocytose-termed the acrosome reaction and the cortical reaction respectively-at different times during their encounter. The success of fertilization depends on these exocytoses. ...
E-mail: [email protected] Abstract: Actin polymerization and development of hyperactivated (HA) motility are two processes that take place during sperm capacitation. Actin polymerization occurs during capacitation and prior to the acrosome reaction fast F-actin breakdown take place. The increase in F-actin during capacitation depends upon inactivation of the actin severing protein, gelsolin, by its binding to phosphatydilinositol-4, 5-bisphosphate (PIP2) and its phosphorylation on tyrosine-438 by Src. Activation of gelsolin by causing its release from PIP2 caused F-actin breakdown and inhibition sperm motility, which could be restored by adding PIP2 to the cells. Reduction of PIP2 synthesis inhibited actin polymerization and motility, and increasing PIP2 synthesis enhanced these activities. Furthermore, sperm demonstrating low motility contained low levels of PIP2 and F-actin. During capacitation there was an increase in PIP2 and F-actin levels in the sperm head and a decrease in the tail. ...
List of Tables xi. Introduction to the Wiley Series on Protein and Peptide Science xiii. Preface xv. Acknowledgments xvii. List of Abbreviations xix. Part A Zona Pellucida Domain Proteins 1. A.1 Nature of the Zona Pellucida Domain 1. A.2 Mouse ZP Proteins 2. A.3 Synthesis, Secretion, and Assembly of ZP Proteins 7. A.4 Structure of the ZPD 13. A.5 Evolution of ZPD Proteins 18. Part B Mammalian Zona Pellucida Proteins 21. B.1 Introduction 21. B.2 Monotremes 22. B.3 Marsupials 24. B.4 Placental Mammals 25. B.4.a Mouse 26. B.4.b Rat 26. B.4.c Hamster 28. B.4.d Rabbit 30. B.4.e Cow 32. B.4.f Pig 33. B.4.g Dog 35. B.4.h Monkey 36. B.4.i Chimpanzee 38. B.4.j Human 40. B.5 Mammalian ZP Proteins as Antifertility Vaccines 45. B.6 Summary Tables 48. Part C Mammalian Zona Pellucida Domain Proteins 53. C.1 Betaglycan/TGFβ?]Receptor Type III 53. C.2 CUB and Zona Pellucida?]like Domain 1 (CUZD?]1) Proteins 55. C.2.a UTCZP/Itmap-1 55. C.2.b UO-44/ERG-1 56. C.3 Deleted in Malignant Brain Tumor 1 (DMBT1) ...
Neoglycoproteins with N-acetylglucosamine residues (BSA-GlcNAc) induced specifically the acrosome reaction (AR) in human spermatozoa. Our objective was to investigate the relationship between this phenomenon and the invitro fertilization (IVF) rate. Sperm suspensions from IVF protocols were incubated with BSA-GlcNAc (t), using calcium ionophore (i) or medium alone (c) as positive or negative controls. When the normalized AR percentage ratio (STIM) (% ARt-%ARc):(%ARi-%ARc) was compared with fertilization rate in 31 couples from our IVF programme, a positive correlation was found (r = 0.46, P , 0.01). The fertilization rate in patients with STIM , or = 0.2 was higher than in non-responders (STIM , 0.2); 72 +/- 7% compared with 5 +/- 3%. The overall predictive value of this test for adequate fertilization rate (, 30%) was 87%, sensitivity 91% and specificity 78%. False positives were 9% and false negatives 22%. For successful fertilization rates (, 60%), the results were: overall predictive value, ...
Membrane lipid regulation of cell function is poorly understood. In early development, sterol efflux and the ganglioside GM1 regulate sperm acrosome exocytosis (AE) and fertilization competence through unknown mechanisms. Here, we show that sterol efflux and focal enrichment of GM1 trigger Ca(2+) influx necessary for AE through CaV2.3, whose activity has been highly controversial in sperm. Sperm lacking CaV2.3s pore-forming α1E subunit showed altered Ca(2+) responses, reduced AE, and a strong subfertility phenotype. Surprisingly, AE depended on spatiotemporal information encoded by flux through CaV2.3, not merely the presence/amplitude of Ca(2+) waves. Using studies in both sperm and voltage clamp of Xenopus oocytes, we define a molecular mechanism for GM1/CaV2.3 regulatory interaction, requiring GM1s lipid and sugar components and CaV2.3s α1E and α2δ subunits. Our results provide a mechanistic understanding of membrane lipid regulation of Ca(2+) flux and therefore Ca(2+)-dependent ...
Pisum sativum|/em| agglutinin is nearly identical in structure and carbohydrate specificity to |em|Lens culinaris|/em| agglutinin.
Study on effects of acrosomal conditions of mammalian spermatozoa on the results of artificial insemination and in vitro fertilizationStudy on effects of acrosomal conditions of mammalian spermatozoa on the results of artificial insemination and in vitro fertilization ...
Sperm antibodies are present in 6% of infertile men. They have sperm coated with antibodies to the extent that sperm function is impaired, particularly sperm-mucus penetration and sperm-zona pellucida binding, resulting in severe infertility.. Natural pregnancy rates without treatment are very low, and fertilization rates with standard IVF are low or zero. Other men have positive Antibodies test, sometimes with tail tip-only binding and normal or only marginally impaired mucus penetration. These low-level sperm antibodies are probably irrelevant to the infertility, and other causes of the couples infertility should be sought. Sperm antibodies can be treated by steroids in immunosuppressive doses. Antibody levels fall, and semen quality improves in about 50% of patients; about 25% produce natural conceptions during a 4- to 6-month course of treatment. There are significant risks of severe side effects, particularly aseptic necrosis of bone. The superior results of ICSI make this treatment ...
View Notes - Chapter 36 Animal Reproduction from BIOL 1006 at Virginia Tech. Chapter 36 Animal Reproduction Vocabulary Acrosome sac at the head of sperm containing enzymes to allow the sperm to
Freshly ejaculated sperm are unable or poorly able to fertilize. Rather, they must first undergo a series of changes known collectively as capacitation. Capacitation is associated with removal of adherent seminal plasma proteins, reorganization of plasma membrane lipids and proteins. It also seems to involve an influx of extracellular calcium, increase in cyclic AMP, and decrease in intracellular pH. The molecular details of capacitation appear to vary somewhat among species. Capacitation occurs while sperm reside in the female reproductive tract for a period of time, as they normally do during gamete transport. The length of time required varies with species, but usually requires several hours. The sperm of many mammals, including humans, can also be capacitated by incubation in certain fertilization media. Sperm that have undergone capacitation are said to become hyperactiviated, and among other things, display hyperactivated motility. Most importantly however, capacitation appears to ...
2007. Zepeda-Bastida A. y A. Mújica. 2007. Involvement of calmodulin on guinea pig sperm nuclei decondensation. First Pan American Congress in Developmental Biology (16-20 de Junio).. ...
That movement of the head is created by a vibration of the stiff anterior portion of the tail, generated by the thrashing movement of the posterior segment remaining outside the zona. 26 Chapter1 oscillations limited scythe-like movement may create a shear-thinning effect on the zona that maximizes the effectiveness of that thrust. In accord with the inference that the movement required for zona penetration generates shear forces at the sperm surface, the inner acrosomal membrane has developed an unusual stability which is inappropriate to a fusogenic role. It is possible that in at least some marsupials complete maturation and oocyte fertilizability are reached after ovulation, following the oocytes arrival in the oviduct (see Chapter 7). Furthermore, in all of the three marsupial genera examined, a loss of the cumulus oophorus from around the egg begins some hours before and is complete at ovulation. This stands in contrast to the eutherian situation, where a full cumulus invests the oocyte ...
Onychophoran sperm share striking apomorphies with sperm of oligochaetes: the elongate, cylindrical, strongly condensed nucleus with (enchytraeid oligochaetes only) spiral keel(s); interpolation of mitochondria, which are spiral as in some microdriles, between nucleus and axoneme (autapomorphy); presence of postmitochondrial annulus; occurrence of a basal cylinder at the anterior end of the two central singlets (autapomorphy). Onychophoran sperm differ notably from oligochaete sperm: in possessing periacrosomal material; in the helical coiling, reduction, or absence of the acrosome vesicle (though acrosomal coiling occurs in leeches); in the conical subacrosomal structure contrasting with the characteristic acrosome tube of euclitellates; in the absence of a perforatorium (though these two features could be consequent on the reduction of the acrosome); in lacking a distinct padlike thickening of the anterior nuclear envelope; in possessing (external to the mutual 9 + 2 axoneme) 9 peripheral ...
This gene belongs to the glutathione peroxidase family. It is specifically expressed in the epididymis in the mammalian male reproductive tract, and is androgen-regulated. Unlike mRNAs for other characterized glutathione peroxidases, this mRNA does not contain a selenocysteine (UGA) codon. Thus, the encoded protein is selenium-independent, and has been proposed to play a role in protecting the membranes of spermatozoa from the damaging effects of lipid peroxidation and/or preventing premature acrosome reaction. (NCBI ...
Authors: TENGHE MA, JIFENG LIU, RUIFENG ZHAO, HAO JIANG, LISHENG DAI, YUMIN ZHAO, ZHIHUI ZHAO, JIABAO ZHANG Abstract: Aquaporin 7 (AQP7) gene as a candidate Antifreeze gene was investigated and associated with fresh and frozen semen quality traits in 45 Simmental and Charolais bulls. PCR-SSCP, PCR-RFLP, and sequencing method were employed to detect the single nucleotide polymorphisms (SNPs) of the AQP7 gene. Two mutations, A264G and G371C, were identified. The allele frequencies were A (0.97, 0.96) to B (0.03, 0.04) and C (0.97, 0.91) to D (0.03, 0.09) in Simmental and Charolais bulls, respectively. A264G substitution was significantly associated with acrosome integrity ratio (P < 0.01) and motility (P < 0.05) in frozen semen. Meanwhile, G371C substitution was significantly associated with acrosome integrity ratio (P < 0.05), percentages of viable sperm (P < 0.05), and motility (P < 0.01) in frozen semen. The results prove that AQP7 gene SNPs are useful for marker-assisted selection in early ...
Synonyms for acrosomal in Free Thesaurus. Antonyms for acrosomal. 7 words related to acrosome: sperm, sperm cell, spermatozoan, spermatozoon, appendage, outgrowth, process. What are synonyms for acrosomal?
An acrosomes is the "cap" at the anterior end of a sperm cell that produces enzymes to facilitate depth of the egg.. Dr. Saint David R. J. Glenn and colleagues information that viagra pic, compared to no view, led to a "sustained enhancement of move," both in Numbers of progressively motile sperm and their velocity.. However, photography to sildenafil - at concentrations relative atomic mass to the mean upper limit sum state density gift 30 minutes after a safety oral dose of 100 milligrams - also led to early activity of the acrosome chemical change. "This has important clinical implications because sperm that acrosome-react before inter-group communication with the oocyte are incapable of fecundation," the researchers note.. "Given that the figure of sperm acrosome react on representation to sildenafil, the drug may proceedings significant debasement to their fertilizing potential drop," they add.. This is a business concern, Dr.Glenn and colleagues say, given that viagra and other ...
Mouse monoclonal antibody raised against native Intra-acrosomal protein. Native purified human intra-acrosomal protein. (MAB3618) - Products - Abnova
ZPBP is one of several proteins that are thought to participate in secondary binding between acrosome-reacted sperm and the egg-specific extracellular matrix, the zona pellucida (McLeskey et al., 1998 [PubMed 9378618]).[supplied by OMIM, Aug 2008 ...
Mountainside, NJ, April 18, 2017 - Androvia LifeSciences announced today the publication of two papers presenting clinical and technology validation studies in the journal Molecular Reproduction and Development, a Wiley publication. These data provide scientific evidence of the clinical utility and value of its breakthrough technology, the Cap-Score™ Sperm Function Test (Cap-Score SFT). A laboratory developed test, the Cap-Score SFT is the only test that can determine if sperm can capacitate, indicating the percentage of sperm that can actually fertilize an egg, and comparing each mans results to a normal, fertile population.. "The Cap-Score Sperm Function Test represents a new frontier in semen analysis and allows us to personalize treatment for couples from the very beginning" said Dr. Fady Sharara, one of the leading fertility specialists in the country and one of the first to offer the test, at his practice the Virginia Center for Reproductive Medicine.. These new publications establish ...
Sperm-egg interactions have been studied for many years using biochemical approaches such as the employment of antibodies and ligands that interact with sperm or with eggs and their vestments. As a result, various factors that participate in fertilization have emerged. However, when animals were genetically manipulated to examine the roles of those factors, most of them were found, to our surprise, to be "not essential". Of course, all biological systems contain redundancies and compensatory mechanisms, but at least some factors were found to be "essential" after gene disruption. As a whole, the explanations of sperm-egg interactions require significant modification from the gene manipulation point of view. In this review, information about sperm-egg interactions obtained from genetically manipulated animals is mainly revisited in order to propose a new vision.
Sperm is the key to conception from the side of the male partner. For this reason, a sperm analysis is the test required to determine the males fertility. How do you prepare for a sperm analysis and how is it done? Read the following article for more information.
Bennett, D and Dunn, L C., "Studies of effects of t-alleles in the house mouse on spermatozoa. I. Male sterility effects." (1967). Subject Strain Bibliography 1967. 576 ...
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ABSTRACT. It is described the sperm ultraestructure differentiation during spermiogenesis of Tagelus plebeius (Lightfoot, 1786). The spermatozoon is an uniflagellated cell of the primitive type. The head region contains a rounded or conical nucleus surrounded by acrosome. The middle piece contains four mitochondria which are arranged around the axoneme. The flagellum contains the usual microtubular axoneme.. Key words: Mollusca, Bivalvia, Tagelus plebeius, ultrastructure, spermatozoa. ...
The mature human spermatozoon is about 60 m long and actively motile. It is divided into head, neck and tail. The head (flattened, about 5 m long and 3 m wide) chiefly consists of the nucleus (greatly condensed chromatin!). The anterior 2/3 of the nucleus is covered by the acrosome, which contains enzymes important in the process of fertilisation. The posterior parts of the nuclear membrane forms the so-called basal plate. The neck is short (about 1 m) and attached to the basal plate. A transversely oriented centriole is located immediately behind the basal plate. The neck also contains nine segmented columns of fibrous material, which continue as the outer dense fibres into the tail. The tail is further divided into a middle piece, a principal piece and an end piece. The axonema (the generic name for the arrangement of microtubules in all cilia) begins in the middle piece. It is surrounded by nine outer dense fibres, which are not found in other cilia. In the middle piece (about 5 m long), the ...
Question - Sperm analysis done. What does the finding indicate? Any solution?. Ask a Doctor about when and why Semen analysis is advised, Ask an Infertility Specialist
Protein Phosphatases Decrease Their Activity during Capacitation: A New Requirement for This Event. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
human progesterone-induced uterine protein-1: a product of secretory endometrial stromal cells; relative mol mass 70,000; isoelectric point 5.7
A recent study evaluates the impact of obesity on sperm health in men. What you need to know about how obesity affects sperm health and male infertility.
Effect of micromolar concentration of Met-AEA on bull heparin-induced sperm capacitation.Spermatozoa were incubated for 45 min at 38.5°C in sp-TALP medium with
2015 - English Adipose-derived stem cells (ASCs) are of a great importance for bone tissue engineering. We compared ASCs obtained by liposuction under two pressures (-200 mmHg and -700 mmHg). The number and proliferation activity of cells isolated under -700 mmHg (ASC-H) were higher than in cells isolated under -200 mmHg (ASC-L). However, the ASC-L was more active in osteogenic differentiation, as manifested by a higher intensity of fluorescence of alkaline phosphatase and osteocalcin in these cells. The adhesion and growth of ASCs were then studied on Ti-6Al-4V samples either unmodified (K, roughness parameter R-a = 280 nm) or modified by shot blasting and tarnishing A, R-a = 200 nm), vibratory finishing (B, R-a = 100 nm) and vibratory finishing, shot blasting and polishing (C, R-a = 80 nm). All modified samples were more wettable than the K samples. On day 1 after seeding, the size of cell spreading area on some modified samples was lower than on K samples, namely on B samples in ASC-L, on B ...
Hiring a professional to undertake cheap air conditioning installation Manly certainly gives you peace of mind. You can be certain that the unit comes with a warranty that offers protection in case the system wears, breaks or fails to operate as required.. Air conditioning in a house comes with tremendous benefits. Having these systems installed in your house properly is key to enjoying these benefits. Since installation might be quite daunting, finding professionals is a prudent idea. Experts such as Balmoral Air Conditioning Services make the whole process a lot easier. Professionals ascertain quality services beyond any reasonable doubt.. ...
The zona pellucida-induced acrosome reaction of human spermatozoa involves extracellular signal-regulated kinase activation  The zona pellucida-induced acrosome reaction of human spermatozoa involves extracellular signal-regulated kinase activation
... like protein during the acrosome reaction (AR) of normal sperm donors and (ii) the role of intact acrosomes during sperm-zone ... G-protein regulation of the solubilized human zona pellucida-mediated acrosome reaction and zona pellucida binding  Bastiaan H ... The present article describes the biological role of ERK during the acrosome reaction of human spermatozoa on stimulation with ... The present article describes the biological role of ERK during the acrosome reaction of human spermatozoa on stimulation with ...
more infohttp://scholar.sun.ac.za/handle/10019.1/13335
Acrosome reaction financial definition of Acrosome reaction  Acrosome reaction financial definition of Acrosome reaction
What is Acrosome reaction? Meaning of Acrosome reaction as a finance term. What does Acrosome reaction mean in finance? ... Definition of Acrosome reaction in the Financial Dictionary - by Free online English dictionary and encyclopedia. ... Related to Acrosome reaction: Cortical reaction, capacitation. Reaction. A decline in prices following an advance. Opposite of ... Acrosome reaction financial definition of Acrosome reaction https://financial-dictionary.thefreedictionary.com/Acrosome+ ...
more infohttps://financial-dictionary.thefreedictionary.com/Acrosome+reaction
Acrosome reaction - Wikipedia  Acrosome reaction - Wikipedia
Therefore, sperm cells go through a process known as the acrosome reaction which is the reaction that occurs in the acrosome of ... which is necessary for initiating the acrosome reaction, the membrane surrounding the acrosome fuses with the plasma membrane ... Since the acrosome reaction has already occurred, sperm are then able to penetrate the zona pellucida due to mechanical action ... The acrosome reaction can be stimulated in vitro by substances a sperm cell may encounter naturally such as progesterone or ...
more infohttps://en.wikipedia.org/wiki/Acrosome_reaction
Acrosome reaction | Article about acrosome reaction by The Free Dictionary  Acrosome reaction | Article about acrosome reaction by The Free Dictionary
Find out information about acrosome reaction. A form of cellular exocytosis that allows sperm to penetrate the zona pellucida ... Related to acrosome reaction: Cortical reaction, capacitation. acrosome reaction. [′ak·rə‚sōm rē‚ak·shən] (cell and molecular ... Acrosome reaction , Article about acrosome reaction by The Free Dictionary https://encyclopedia2.thefreedictionary.com/acrosome ... a href=https://encyclopedia2.thefreedictionary.com/acrosome+reaction,acrosome reaction,/a,. *Facebook ...
more infohttps://encyclopedia2.thefreedictionary.com/acrosome+reaction
IDEALS @ Illinois: Re-localization of SNARE proteins in mouse sperm prior to the acrosome reaction  IDEALS @ Illinois: Re-localization of SNARE proteins in mouse sperm prior to the acrosome reaction
Acrosome Reaction. Abstract:. The principal role of SNARE proteins is to arbitrate vesicle fusion to a target membrane. ... During the sperm acrosome reaction, the outer acrosomal membrane fuses at hundreds of points with the overlying plasma membrane ... Re-localization of SNARE proteins in mouse sperm prior to the acrosome reaction. Welcome to the IDEALS Repository. ... We hypothesize that syntaxin and synaptobrevin re-localize within the sperm plasma membrane prior to the acrosome reaction to ...
more infohttps://www.ideals.illinois.edu/handle/2142/78670
Zona pellucida mediated acrosome reaction and sperm morphology  Zona pellucida mediated acrosome reaction and sperm morphology
... Franken D.R. ; Bastiaan H.S. ; Kidson A. ; Wranz P. ; Habenicht ... spontaneous and calcium ionophore induced acrosome reaction. Predictive values for acrosome responsiveness were depicted with ... After completion of acrosome reaction studies, patient samples were divided according to the percentage of morphologically ... Sperm samples from 29 men randomly selected from the andrology laboratory, were used to evaluate acrosome reaction response to ...
more infohttp://scholar.sun.ac.za/handle/10019.1/13342
SUE - Acrosome Reaction  SUE - Acrosome Reaction
ACROSOME REACTION The red receptors on the sperm come into contact with the egg jelly, yellow. This induces the acrosome ... reaction causing the acrosome in green to fuse with the plasma membrane of the sperm. The actin in pink goes from a globular ...
more infohttps://web.stanford.edu/group/Urchin/acrosome.htm
Sperm biology and control of reproduction in sturgeon: (II) sperm morphology, acrosome reaction, motility and cryopreservation,...  Sperm biology and control of reproduction in sturgeon: (II) sperm morphology, acrosome reaction, motility and cryopreservation,...
... acrosome reaction, motility and cryopreservation, Reviews in Fish Biology and Fisheries" on DeepDyve, the largest online rental ... Sperm biology and control of reproduction in sturgeon: (II) sperm morphology, acrosome reaction,... Alavi, Sayyed; Hatef, ... Egg water, Ca2+ and Mg2+ can trigger acrosome reaction. Trypsin- and chymotrypsin-like activities are reported in sturgeon ... Egg water, Ca2+ and Mg2+ can trigger acrosome reaction. Trypsin- and chymotrypsin-like activities are reported in sturgeon ...
more infohttps://www.deepdyve.com/lp/springer_journal/sperm-biology-and-control-of-reproduction-in-sturgeon-ii-sperm-LFMPeeh14n
Monoclonal antibodies which recognize equatorial segment epitopes presented de novo following the A23187-induced acrosome...  Monoclonal antibodies which recognize equatorial segment epitopes presented de novo following the A23187-induced acrosome...
This suggests that the acrosome reaction results in presentation of at least one novel epitope which plays a role in sperm- ... When sperm were induced to undergo the acrosome reaction with A23187 and incubated with their discharged acrosomal contents, a ... Formaldehyde fixation of acrosome-intact sperm caused partial rupture of the acrosome with loss of the characteristic rouleaux ... Acrosome-intact mammalian sperm can adhere to zona pellucida-free oocytes but are only capable of fusing if they have ...
more infohttp://jcs.biologists.org/content/108/2/767
Progesterone in mare follicular fluid induces the acrosome reaction in stallion spermatozoa and enhances in vitro binding to...  Progesterone in mare follicular fluid induces the acrosome reaction in stallion spermatozoa and enhances in vitro binding to...
... induces the acrosome reaction (AR) in stallion spermatozoa and, if so, to identify the component in FF responsible for it. ... Viable spermatozoa without the outer acrosomal membrane were considered as physiologically acrosome-reacted. Results showed ... The aim of this study was to investigate whether mare follicular fluid (FF) induces the acrosome reaction (AR) in stallion ... Progesterone in mare follicular fluid induces the acrosome reaction in stallion spermatozoa and enhances in vitro binding to ...
more infohttps://www.semanticscholar.org/paper/Progesterone-in-mare-follicular-fluid-induces-the-Cheng-Fazeli/d69692be6dccbcbd20582be6a791e1c119a7aa72
EMF-Portal | The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona...  EMF-Portal | The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona...
2012): RE:The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona binding ... Lerchl A (2012): Letter on The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry ... The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona binding of human ... The irradiation did not affect the acrosome reaction. The analysis of morphometric parameters revealed a statistically ...
more infohttps://www.emf-portal.org/en/article/18046
Effects of pentoxifylline and progesterone on human sperm capacitation and acrosome reaction. - Semantic Scholar  Effects of pentoxifylline and progesterone on human sperm capacitation and acrosome reaction. - Semantic Scholar
Stimulation of both capacitation and acrosome reaction resulted from sequential exposure to pentoxifylline and progesterone. ... After exposure to pentoxifylline (1 mg/ml; 30 min), the fluorescent B pattern, characteristic of capacitated, acrosome-intact ... acrosome loss and hyperactivation. Sperm viability was not affected in any treatment group. These observations suggest that ... cells, increased significantly (P , 0.01), though no increase in AR pattern, characteristic of acrosome-reacted cells, was ...
more infohttps://www.semanticscholar.org/paper/Effects-of-pentoxifylline-and-progesterone-on-huma-Kay-Coutts/8d9644b160b41d3a5a85b5d8ec358bb34870a517
Nitric oxide involvement in the acrosome reaction triggered by leptin in pig sperm | Reproductive Biology and Endocrinology |...  Nitric oxide involvement in the acrosome reaction triggered by leptin in pig sperm | Reproductive Biology and Endocrinology |...
... a maturation step preceding acrosome reaction. Recent studies have reported leptin ability to promote capacitation and acrosome ... Furthermore, the inhibitory effect of L-NAME and of Ab-ObR on the promotion of acrosome reaction triggered by leptin suggests a ... Significant increases of nitric oxide levels and acrosome reaction extent were detected in leptin-treated spermatozoa, but both ... In addition, acrosome status of treated-spermatozoa was evaluated by FITC-PNA staining. ...
more infohttps://rbej.biomedcentral.com/articles/10.1186/1477-7827-9-133
Fusion of membranes during the acrosome reaction: a tale of tw...  Fusion of membranes during the acrosome reaction: a tale of tw...
Fusion of membranes during the acrosome reaction: a tale of two SNAREs.: During spermiogenesis, hydrolytic enzymes are sorted ... Fusion of membranes during the acrosome reaction: a tale of two SNAREs.. Authors * Kierszenbaum, A L ... Syntaxin 2, a v-SNARE member, and Rab3A, a member of the Rab GTPases, have been localized in the acrosome of rodent sperm. ... At fertilization, the enzymatic content of the acrosome is released by exocytosis when a portion of the plasma membrane ...
more infohttps://www.mysciencework.com/publication/show/fusion-membranes-during-acrosome-reaction-tale-two-snares-39556188
Human sperm motility, capacitation and acrosome reaction are impaired by 2-arachidonoylglycerol endocannabinoid.  Human sperm motility, capacitation and acrosome reaction are impaired by 2-arachidonoylglycerol endocannabinoid.
... * Posted on ... In this work, we have demonstrated that 2AG induces the spontaneous acrosome reaction and reduces progressive motility in fresh ... During the capacitation technique, sperm becomes more sensitive to low concentrations of 2AG, triggering the acrosome reaction ... Tags: 2-arachidonoylglycerol, 2AG, capacitation and acrosome reaction, endocannabinoid, Human sperm motility ...
more infohttp://freedomwares.ca/human-sperm-motility-capacitation-acrosome-reaction-impaired-2-arachidonoylglycerol-endocannabinoid/
Capacitation-associated Changes in Protein-tyrosine-phosphorylation, Hyperactivation and Acrosome Reaction in Guinea Pig Sperm
...  Capacitation-associated Changes in Protein-tyrosine-phosphorylation, Hyperactivation and Acrosome Reaction in Guinea Pig Sperm ...
Moreover, an absence of $Ca^{2+}$ or $HCO_3{^-}$ inhibited in vitro hyperactivation and acrosome reaction and decreased the ... hyperactivation and acrosome reaction in guinea pig sperm. Caudal epididymal sperm were incubated in four different groups: ... Hyperactivation and Acrosome Reaction in Guinea Pig Sperm Acrosome Reaction;Capacitation;Hyperactivation;Tyrosine ... A molecular membrane model of sperm capacitation and the acrosome reaction of mammalian spermatozoa. Gamete Res. 12:183-224. ...
more infohttp://koreascience.or.kr/article/JAKO200810103463866.page?lang=ko
Capacitation-associated Changes in Protein-tyrosine-phosphorylation, Hyperactivation and Acrosome Reaction in Guinea Pig Sperm
...  Capacitation-associated Changes in Protein-tyrosine-phosphorylation, Hyperactivation and Acrosome Reaction in Guinea Pig Sperm ...
Moreover, an absence of $Ca^{2+}$ or $HCO_3{^-}$ inhibited in vitro hyperactivation and acrosome reaction and decreased the ... hyperactivation and acrosome reaction in guinea pig sperm. Caudal epididymal sperm were incubated in four different groups: ... Hyperactivation and Acrosome Reaction in Guinea Pig Sperm Acrosome Reaction;Capacitation;Hyperactivation;Tyrosine ... A molecular membrane model of sperm capacitation and the acrosome reaction of mammalian spermatozoa. Gamete Res. 12:183-224. ...
more infohttp://koreascience.or.kr/article/JAKO200810103463866.page?lang=en
Google Books  Google Books
Human Sperm Acrosome Reaction. Patrick F nichel, Jean Parinaud - Fertilization (Biology) - 1995 - 460 pages. ...Human homolog ...
more infohttps://books.google.com/books?id=UEvbQcZ7e1oC&qtid=217e79f2&source=gbs_quotes_r&cad=6
Marine Drugs  | Free Full-Text | Effect of Astaxanthin on Human Sperm Capacitation | HTML  Marine Drugs | Free Full-Text | Effect of Astaxanthin on Human Sperm Capacitation | HTML
... study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome- ... plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red ... Evaluation of Acrosome Reaction. Acrosome status was monitored with acrosome-specific FITC-labeled peanut (Arachis hypogaea) ... Effect of Asta on Sperm Viability and Acrosome Reaction (AR). At the end of incubation, aliquots of sperm suspensions were ...
more infohttp://www.mdpi.com/1660-3397/11/6/1909/htm
PLCζ is the physiological trigger of the Ca2+ oscillations that induce embryogenesis in mammals but conception can occur in its...  PLCζ is the physiological trigger of the Ca2+ oscillations that induce embryogenesis in mammals but conception can occur in its...
Acrosome reaction. Spermatozoa were collected as before, washed, then capacitated in complete HTF medium for 30 min at 37°C and ... 3E-G). Additionally, the ability of Plcz1- sperm to undergo the acrosome reaction in response to either progesterone or ... D-G) Analysis of sperm motility parameters using computer-assisted sperm analysis (CASA). (H) An acrosome reaction was induced ... hyperactivity and ability to undergo the acrosome reaction. This is in contrast to a previous preliminary report that claimed ...
more infohttp://dev.biologists.org/content/144/16/2914
  • The mean percentage (±SE) ZP mediated acrosome reacted sperm among teratozoospermic and severely teratozoospermic cases was 25.8% ± 0.9 and 19.0% ± 0.9 (P= 0.001), compared to 36.8%±0.9 for the donor controls. (sun.ac.za)
  • Monoclonal antibodies were raised against unfixed acrosome-reacted guinea pig sperm and screened by indirect immunofluorescence for binding to the equatorial segment. (biologists.org)
  • Formaldehyde fixation of acrosome-intact sperm caused partial rupture of the acrosome with loss of the characteristic rouleaux (stacks) of guinea pig sperm. (biologists.org)
  • In the first part of this paper, we present a novel tool (the TAT-cAMP sponge) to investigate cAMP-related signaling pathways in response to progesterone as acrosome reaction trigger. (nih.gov)
  • Cryosections of acrosome-intact sperm labelled indirectly with immuno-gold showed labelling consistent with the same location, as well as sporadic labelling at other intracellular sites overlying the acrosome. (biologists.org)
  • Therefore, the expression of intracellular NOS enzymes has been also assessed and the possible involvement of NO in acrosome reaction triggered by leptin has been evaluated. (biomedcentral.com)
  • The mitogen-activated protein kinase (MAP kinase) pathway participates in a number of reactions of the cell when responding to various external stimuli. (sun.ac.za)
  • During the capacitation technique, sperm becomes more sensitive to low concentrations of 2AG, triggering the acrosome reaction and inhibiting protein phosphorylation. (freedomwares.ca)
  • The expression of SUMO-1 in the acrosome region of water buffalo sperm and the identification of potentially SUMOylated proteins important for sperm function implicates sumoylation as a crucial PTM related to sperm function. (frontiersin.org)
  • p>This subsection of the 'Function' section describes an enzyme regulatory mechanism and reports the components which regulate (by activation or inhibition) the reaction. (uniprot.org)
  • During spermiogenesis, hydrolytic enzymes are sorted from the Golgi apparatus to the acrosome, a supranuclear megavesicle. (mysciencework.com)
  • In recent reports, we showed that human sperm endogenous ROS production is essential for correct capacitation, evaluated as the percentage of acrosome-reacted cells (ARC) directly dependent on Tyr-phosphorylation (Tyr-P) of the sperm head [ 11 ]. (mdpi.com)
  • Furthermore, the inhibitory effect of L -NAME and of Ab-ObR on the promotion of acrosome reaction triggered by leptin suggests a possible involvement of NO in the hormone action. (biomedcentral.com)
  • Thus, we have been able to elicit an egg-induced dissociation of the receptor and acrosome reaction-inducing activities of the ZP, which should provide a means to study the components of ZP3 involved in the acrosome reaction. (springer.com)
  • p>This subsection of the 'Function' section describes the catalytic activity of an enzyme, i.e. the chemical reaction it catalyzes. (uniprot.org)