Neuroendocrine Secretory Protein 7B2
Neuroendocrine Tumors
Carcinoma, Neuroendocrine
Neurosecretory Systems
Neuroendocrine Cells
Prostatic Secretory Proteins
Chromogranins
Chromogranin A
Uteroglobin
Epididymal Secretory Proteins
Seminal Plasma Proteins
Salivary Proteins and Peptides
Carcinoid Tumor
Endoplasmic Reticulum
Chromogranin B
Chymotrypsinogen
Proteins
Golgi Apparatus
The neuroendocrine protein 7B2 is required for peptide hormone processing in vivo and provides a novel mechanism for pituitary Cushing's disease. (1/59)
The neuroendocrine protein 7B2 has been implicated in activation of prohormone convertase 2 (PC2), an important neuroendocrine precursor processing endoprotease. To test this hypothesis, we created a null mutation in 7B2 employing a novel transposon-facilitated technique and compared the phenotypes of 7B2 and PC2 nulls. 7B2 null mice have no demonstrable PC2 activity, are deficient in processing islet hormones, and display hypoglycemia, hyperproinsulinemia, and hypoglucagonemia. In contrast to the PC2 null phenotype, these mice show markedly elevated circulating ACTH and corticosterone levels, with adrenocortical expansion. They die before 9 weeks of severe Cushing's syndrome arising from pituitary intermediate lobe ACTH hypersecretion. We conclude that 7B2 is indeed required for activation of PC2 in vivo but has additional important functions in regulating pituitary hormone secretion. (+info)Pro-opiomelanocortin-related peptides, prohormone convertases 1 and 2 and the regulatory peptide 7B2 are present in melanosomes of human melanocytes. (2/59)
Recently, it has been shown that alpha-melanocyte stimulating hormone can directly activate tyrosinase by removing the allosteric regulator 6(R)-L-erythro 5,6,7,8 tetrahydrobiopterin resulting in a stable alpha-melanocyte stimulating hormone/6(R)-L-erythro 5,6,7,8 tetrahydrobiopterin complex. As melanin production occurs in the melanosome, a specific organelle of the melanocyte, it seemed important to investigate whether these organelles themselves actually produce pro-opiomelanocortin-related peptides in their acidic environment. The presence of alpha-melanocyte stimulating hormone and adrenocorticotropin in the epidermis and melanocytes has been shown by several investigators. In order to follow possible pro-opiomelanocortin processing in the melanosome, human melanocytes were established in MCDB 153 medium and utilized for immunohistochemistry, immunogold electron microscopy, and western blotting. For this purpose antibodies against alpha-melanocyte stimulating hormone, adrenocorticotropin, prohormone convertases 1 and 2 (PC1 and PC2) and the PC2 regulatory protein 7B2 were used. Our results demonstrated the presence of the entire system for pro-opiomelanocortin processing in the melanosome. Considering the pH optima of these convertases, the results are in agreement with an autocrine intramelanosomal production of pro- opiomelanocortin-related peptides and an autocrine production and recycling of the cofactor 6(R)-L- erythro 5,6,7,8 tetrahydrobiopterin in melanocytes. Based on these novel observations, we would like to propose that the pigmentation process may not necessarily involve a melanocortin-1 receptor-mediated mechanism. (+info)Interaction of Drosophila melanogaster prohormone convertase 2 and 7B2. Insect cell-specific processing and secretion. (3/59)
The prohormone convertases (PCs) are an evolutionarily ancient group of proteases required for the maturation of neuropeptide and peptide hormone precursors. In Drosophila melanogaster, the homolog of prohormone convertase 2, dPC2 (amontillado), is required for normal hatching behavior, and immunoblotting data indicate that flies express 80- and 75-kDa forms of this protein. Because mouse PC2 (mPC2) requires 7B2, a helper protein for productive maturation, we searched the fly data base for the 7B2 signature motif PPNPCP and identified an expressed sequence tag clone encoding the entire open reading frame for this protein. dPC2 and d7B2 cDNAs were subcloned into expression vectors for transfection into HEK-293 cells; mPC2 and rat 7B2 were used as controls. Although active mPC2 was detected in medium in the presence of either d7B2 or r7B2, dPC2 showed no proteolytic activity upon coexpression of either d7B2 or r7B2. Labeling experiments showed that dPC2 was synthesized but not secreted from HEK-293 cells. However, when dPC2 and either d7B2 or r7B2 were coexpressed in Drosophila S2 cells, abundant immunoreactive dPC2 was secreted into the medium, coincident with the appearance of PC2 activity. Expression and secretion of dPC2 enzyme activity thus appears to require insect cell-specific posttranslational processing events. The significant differences in the cell biology of the insect and mammalian enzymes, with 7B2 absolutely required for secretion of dPC2 and zymogen conversion occurring intracellularly in the case of dPC2 but not mPC2, support the idea that the Drosophila enzyme has specific requirements for maturation and secretion that can be met only in insect cells. (+info)Mutations in the catalytic domain of prohormone convertase 2 result in decreased binding to 7B2 and loss of inhibition with 7B2 C-terminal peptide. (4/59)
Prohormone convertases 1 (PC1) and 2 (PC2) are members of a family of subtilisin-like proprotein convertases responsible for proteolytic maturation of a number of different prohormones and proneuropeptides. Although sharing more than 50% homology in their catalytic domains, PC1 and PC2 exhibit differences in substrate specificity and susceptibility to inhibitors. In addition to these differences, PC2, unlike PC1 and other members of the family, specifically binds the neuroendocrine protein 7B2. In order to identify determinants responsible for the specific properties of the PC2 catalytic domain, we compared its primary sequence with that of other PCs. This allowed us to distinguish a PC2-specific sequence at positions 242-248. We constructed two PC2 mutants in which residues 242 and 243 and residues 242-248 were replaced with the corresponding residues of PC1. Studies of in vivo cleavage of proenkephalin, in vivo production of alpha-MSH from proopiomelanocortin, and in vitro cleavage of a PC2-specific artificial substrate by mutant PC2s did not reveal profound alterations. On the other hand, both mutant pro-PC2s exhibited a considerably reduced ability to bind to 21-kDa 7B2. In addition, inhibition of mutant PC2-(242-248) by the potent natural inhibitor 7B2 CT peptide was almost completely abolished. Taken together, our results show that residues 242-248 do not play a significant role in defining the substrate specificity of PC2 but do contribute greatly to binding 7B2 and are critical for inhibition with the 7B2 CT peptide. (+info)The SAAS granin exhibits structural and functional homology to 7B2 and contains a highly potent hexapeptide inhibitor of PC1. (5/59)
Prohormone convertases (PCs) 1 and 2 are thought to mediate the proteolytic cleavage of many peptide precursors. Endogenous inhibitors of both PC1 and PC2 have now been identified; the 7B2 protein is a nanomolar inhibitor of PC2, while the novel protein proSAAS was recently reported to be a micromolar inhibitor of PC1 [Fricker et al. (2000) J. Neurosci. 20, 639-648]. We here report evidence that 7B2 and proSAAS exhibit several elements of structural and functional homology. Firstly, 26 kDa human, mouse and rat proSAAS, like all vertebrate 7B2s, contain a proline-rich sequence within the first half of the molecule and also contain a C-terminal 40 residue peptide (SAAS CT peptide) separated from the remainder of the protein by a furin consensus sequence. The SAAS CT peptide contains the precise sequence of a hexapeptide previously identified by combinatorial peptide library screening as a potent inhibitor of PC1, and the vast majority of the inhibitory potency of proSAAS can be attributed to this hexapeptide. Further, like the 7B2 CT peptide, SAAS CT-derived peptides represent tight-binding competitive convertase inhibitors with nanomolar potencies. Lastly, recombinant PC1 is able to cleave the proSAAS CT peptide to a product with a mass consistent with cleavage following the inhibitory hexapeptide. Taken together, our results indicate that proSAAS and 7B2 may comprise two members of a functionally homologous family of convertase inhibitor proteins. (+info)Expression of proopiomelanocortin peptides in human dermal microvascular endothelial cells: evidence for a regulation by ultraviolet light and interleukin-1. (6/59)
Proopiomelanocortin peptides such as alpha-melanocyte-stimulating hormone and adrenocorticotropin are expressed in the epidermal and dermal compartment of the skin after noxious stimuli and are recognized as modulators of immune and inflammatory reactions. Human dermal microvascular endothelial cells mediate leukocyte-endothelial interactions during cutaneous inflammation by the expression of cellular adhesion molecules and cytokines such as interleukin-1. This study addresses the hypothesis that human dermal microvascular endothelial cells express both proopiomelanocortin and prohormone convertases, which are required to generate proopiomelanocortin peptides. Semiquantitative reverse transcriptase polymerase chain reaction and northern blot studies revealed a constitutive expression of proopiomelanocortin mRNA by human dermal microvascular endothelial cells in vitro that was time- and concentration-dependently upregulated by interleukin-1 beta. Furthermore, irradiation of human dermal microvascular endothelial cells with ultraviolet A1 (30J per cm(2)) or ultraviolet B (12.5 mJ per cm(2)) enhanced proopiomelanocortin expression as well as the production and release of the proopiomelanocortin peptides adrenocorticotropin and alpha-melanocyte-stimulating hormone. In addition to proopiomelanocortin, prohormone convertase 1 mRNA expression was detected by reverse transcriptase polymerase chain reaction in unstimulated human dermal microvascular endothelial cells and was augmented after exposure to alpha-melanocyte- stimulating hormone, interleukin-1 beta, or irradiation with ultraviolet. These findings demonstrate that human dermal microvascular endothelial cells express proopiomelanocortin and prohormone convertase 1 required for the generation of adrenocorticotropin. Additionally, human dermal microvascular endothelial cells express mRNA for the prohormone convertase 2 binding protein 7B2. Taken together these findings indicate that human dermal microvascular endothelial cells upon stimulation express both proopiomelanocortin and prohormone convertases required for the generation of alpha-melanocyte-stimulating hormone. As proopiomelanocortin peptides were found to regulate the production of human dermal microvascular endothelial cell cytokines and adhesion molecules and to have a variety of anti-inflammatory properties these peptides may significantly contribute to the modulation of skin inflammation. J Invest Dermatol 115:1021-1028 2000 (+info)Neuroendocrine secretory protein 7B2: structure, expression and functions. (7/59)
7B2 is an acidic protein residing in the secretory granules of neuroendocrine cells. Its sequence has been elucidated in many phyla and species. It shows high similarity among mammals. A Pro-Pro-Asn-Pro-Cys-Pro polyproline motif is its most conserved feature, being carried by both vertebrate and invertebrate sequences. It is biosynthesized as a precursor protein that is cleaved into an N-terminal fragment and a C-terminal peptide. In neuroendocrine cells, 7B2 functions as a specific chaperone for the proprotein convertase (PC) 2. Through the sequence around its Pro-Pro-Asn-Pro-Cys-Pro motif, it binds to an inactive proPC2 and facilitates its transport from the endoplasmic reticulum to later compartments of the secretory pathway where the zymogen is proteolytically matured and activated. Its C-terminal peptide can inhibit PC2 in vitro and may contribute to keep the enzyme transiently inactive in vivo. The PC2-7B2 model defines a new neuroendocrine paradigm whereby proteolytic activation of prohormones and proneuropeptides in the secretory pathway is spatially and temporally regulated by the dynamics of interactions between converting enzymes and their binding proteins. Interestingly, unlike PC2-null mice, which are viable, 7B2-null mutants die early in life from Cushing's disease due to corticotropin ('ACTH') hypersecretion by the neurointermediate lobe, suggesting a possible involvement of 7B2 in secretory granule formation and in secretion regulation. The mechanism of this regulation is yet to be elucidated. 7B2 has been shown to be a good marker of several neuroendocrine cell dysfunctions in humans. The possibility that anomalies in its structure and expression could be aetiological causes of some of these dysfunctions warrants investigation. (+info)Functional characterization of ProSAAS: similarities and differences with 7B2. (8/59)
Prohormone convertases (PC) 1 and 2, enzymes found primarily in neuroendocrine tissues, are thought to mediate the proteolytic cleavage of many peptide precursors. To date, endogenous binding proteins for both PC2 (7B2) and PC1 (proSAAS) have been identified. Although 7B2 represents a potent inhibitor of PC2, the most important function of 7B2 as regards this enzyme appears to be the absolute requirement of PC2 for 7B2 in the generation of active enzyme, recently corroborated through production of a null animal that lacks PC2 activity. The purpose of the present study was to determine whether proSAAS exerts effects on PC1 other than inhibition, and to establish functional similarities and differences between 7B2 and proSAAS. We first asked whether the N-terminal domain of proSAAS (proSAAS-(1-180)) could stabilize PC1 activity, similar to the effect of the N-terminal domain of 7B2 on PC2. Recombinant His-tagged proSAAS-(1-180) had no effect on PC1 activity in vitro and was unable to protect PC1 from thermal denaturation. Transient cotransfection of proSAAS-(1-225) cDNA with PC1 cDNA into HEK 293 cells reduced the amount of PC1 activity detected in the medium. Surprisingly, cotransfection of proSAAS-(1-180) cDNA, encoding a protein that lacks the inhibitory C-terminal domain peptide, also reduced the activity of PC1 detected in the medium, but the mass of PC1 secreted into the medium was increased, suggesting a proSAAS-mediated inactivation reaction. Similar results were observed in CHO/PC1 cells stably transfected with pro-SAAS-(1-180). Stable transfection of SAAS cDNAs into AtT-20 cells was used to examine the role of proSAAS in a neuroendocrine setting. Unlike 7B2, proSAAS-(1-225) was able to slow convertase-mediated processing of proopiomelanocortin and proenkephalin; however, similarly to 7B2, proSAAS expression did not result in any accumulated differences in the content of cellular processed peptide. In summary, although both proSAAS and 7B2 potently inhibit PC enzymes via a C-terminal peptide, their intracellular interactions with PCs appear to differ significantly, with each binding protein exhibiting unique properties. (+info)Neuroendocrine Secretory Protein 7B2 (NESP7B2) is defined as a protein that is encoded by the 7B2 gene in humans. This protein is primarily produced in neuroendocrine cells, including those found in the brain and the endocrine system. NESP7B2 has a molecular weight of approximately 29 kDa and is composed of 256 amino acids.
One of the primary functions of NESP7B2 is to regulate the activity of another protein called prohormone convertase 2 (PC2). PC2 is involved in the processing and activation of various hormones and neurotransmitters, and NESP7B2 helps to control its activity by binding to it and inhibiting its action.
NESP7B2 has also been found to have a role in the regulation of calcium homeostasis and may be involved in the development and function of the nervous system. Mutations in the 7B2 gene have been associated with certain medical conditions, including some forms of cancer and neurological disorders.
Neuroendocrine tumors (NETs) are a diverse group of neoplasms that arise from cells of the neuroendocrine system, which is composed of dispersed neuroendocrine cells throughout the body, often in close association with nerves and blood vessels. These cells have the ability to produce and secrete hormones or hormone-like substances in response to various stimuli. NETs can occur in a variety of organs, including the lungs, pancreas, small intestine, colon, rectum, stomach, and thyroid gland, as well as in some less common sites such as the thymus, adrenal glands, and nervous system.
NETs can be functional or nonfunctional, depending on whether they produce and secrete hormones or hormone-like substances that cause specific symptoms related to hormonal excess. Functional NETs may give rise to a variety of clinical syndromes, such as carcinoid syndrome, Zollinger-Ellison syndrome, pancreatic neuroendocrine tumor syndrome (also known as Verner-Morrison or WDHA syndrome), and others. Nonfunctional NETs are more likely to present with symptoms related to the size and location of the tumor, such as abdominal pain, intestinal obstruction, or bleeding.
The diagnosis of NETs typically involves a combination of imaging studies, biochemical tests (e.g., measurement of serum hormone levels), and histopathological examination of tissue samples obtained through biopsy or surgical resection. Treatment options depend on the type, location, stage, and grade of the tumor, as well as the presence or absence of functional symptoms. They may include surgery, radiation therapy, chemotherapy, targeted therapy, and/or peptide receptor radionuclide therapy (PRRT).
Carcinoma, neuroendocrine is a type of cancer that arises from the neuroendocrine cells, which are specialized cells that have both nerve and hormone-producing functions. These cells are found throughout the body, but neuroendocrine tumors (NETs) most commonly occur in the lungs, gastrointestinal tract, pancreas, and thyroid gland.
Neuroendocrine carcinomas can be classified as well-differentiated or poorly differentiated based on how closely they resemble normal neuroendocrine cells under a microscope. Well-differentiated tumors tend to grow more slowly and are less aggressive than poorly differentiated tumors.
Neuroendocrine carcinomas can produce and release hormones and other substances that can cause a variety of symptoms, such as flushing, diarrhea, wheezing, and heart palpitations. Treatment for neuroendocrine carcinoma depends on the location and extent of the tumor, as well as the patient's overall health. Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapy, or a combination of these approaches.
Neurosecretory systems are specialized components of the nervous system that produce and release chemical messengers called neurohormones. These neurohormones are released into the bloodstream and can have endocrine effects on various target organs in the body. The cells that make up neurosecretory systems, known as neurosecretory cells, are found in specific regions of the brain, such as the hypothalamus, and in peripheral nerves.
Neurosecretory systems play a critical role in regulating many physiological processes, including fluid and electrolyte balance, stress responses, growth and development, reproductive functions, and behavior. The neurohormones released by these systems can act synergistically or antagonistically to maintain homeostasis and coordinate the body's response to internal and external stimuli.
Neurosecretory cells are characterized by their ability to synthesize and store neurohormones in secretory granules, which are released upon stimulation. The release of neurohormones can be triggered by a variety of signals, including neural impulses, hormonal changes, and other physiological cues. Once released into the bloodstream, neurohormones can travel to distant target organs, where they bind to specific receptors and elicit a range of responses.
Overall, neurosecretory systems are an essential component of the neuroendocrine system, which plays a critical role in regulating many aspects of human physiology and behavior.
Neuroendocrine cells are specialized cells that are found throughout the body, but primarily in the respiratory and digestive tracts. These cells have characteristics of both neurons and endocrine cells. Like neurons, neuroendocrine cells can receive and transmit signals to other cells using chemical messengers called neurotransmitters. Like endocrine cells, they can produce and secrete hormones into the bloodstream, where they can travel to other parts of the body and affect the function of distant organs.
Neuroendocrine cells are responsible for a variety of physiological functions, including regulating air and blood flow in the lungs, controlling the motility and secretion of the gastrointestinal tract, and modulating immune responses. They can also play a role in the development and progression of certain diseases, such as neuroendocrine tumors, which are rare but aggressive cancers that can arise from these cells.
Anatomically, neuroendocrine cells can be found as scattered individual cells or as clusters of cells called neuroepithelial bodies. They are characterized by the presence of dense-core granules containing hormones and neurotransmitters, which can be released in response to various stimuli. Neuroendocrine cells can also express a variety of receptors, including those for neurotransmitters, hormones, and growth factors, which allow them to respond to signals from other cells and modulate their own activity.
Prostatic secretory proteins are a group of proteins that are produced and secreted by the prostate gland, which is a small gland that is part of the male reproductive system. These proteins play an important role in maintaining the health and function of the reproductive system.
One of the most well-known prostatic secretory proteins is prostate-specific antigen (PSA), which is often used as a biomarker for the early detection and monitoring of prostate cancer. PSA is a protein that is produced by the cells in the prostate gland and is normally found in low levels in the blood. However, when the prostate gland becomes enlarged or cancerous, the levels of PSA in the blood can increase, making it possible to detect these conditions through a simple blood test.
Other prostatic secretory proteins include prostate-specific acid phosphatase (PSAP), prostatein, and prolactin-inducible protein (PIP). These proteins are also produced by the prostate gland and have various functions, such as helping to liquefy semen and protecting sperm from the immune system.
It is important to note that while these proteins can provide valuable information about the health of the prostate gland, they are not foolproof indicators of disease. Other factors, such as age, inflammation, and benign prostatic hyperplasia (BPH), can also affect the levels of these proteins in the blood. Therefore, it is important to consult with a healthcare professional for proper interpretation and follow-up care.
Chromogranins are a group of proteins that are stored in the secretory vesicles of neuroendocrine cells, including neurons and endocrine cells. These proteins are co-released with neurotransmitters and hormones upon stimulation of the cells. Chromogranin A is the most abundant and best studied member of this protein family.
Chromogranins have several functions in the body. They play a role in the biogenesis, processing, and storage of neuropeptides and neurotransmitters within secretory vesicles. Additionally, chromogranins can be cleaved into smaller peptides, some of which have hormonal or regulatory activities. For example, vasostatin-1, a peptide derived from chromogranin A, has been shown to have vasodilatory and cardioprotective effects.
Measurement of chromogranin levels in blood can be used as a biomarker for the diagnosis and monitoring of neuroendocrine tumors, which are characterized by excessive secretion of chromogranins and other neuroendocrine markers.
Chromogranin A is a protein that is widely used as a marker for neuroendocrine tumors. These are tumors that arise from cells of the neuroendocrine system, which is a network of cells throughout the body that produce hormones and help to regulate various bodily functions. Chromogranin A is stored in secretory granules within these cells and is released into the bloodstream when the cells are stimulated to release their hormones.
Chromogranin A is measured in the blood as a way to help diagnose neuroendocrine tumors, monitor the effectiveness of treatment, and track the progression of the disease. Elevated levels of chromogranin A in the blood may indicate the presence of a neuroendocrine tumor, although other factors can also cause an increase in this protein.
It's important to note that while chromogranin A is a useful marker for neuroendocrine tumors, it is not specific to any one type of tumor and should be used in conjunction with other diagnostic tests and clinical evaluation.
Uteroglobin, also known as blastokinin or Clara cell 10-kDa protein (CC10), is a small molecular weight protein that is abundantly present in the respiratory tract and reproductive system of many mammals. It was first identified in the uterine fluid of pregnant animals, hence its name.
In the human body, uteroglobin is primarily produced by non-ciliated bronchial epithelial cells known as Clara cells, which are located in the respiratory tract. Uteroglobin has been found to have anti-inflammatory and immunomodulatory properties, and it may play a role in protecting the lungs from injury and inflammation.
In the reproductive system, uteroglobin is produced by the endometrial glands of the uterus during pregnancy, and it has been suggested to have a role in maintaining pregnancy and promoting fetal growth. However, its precise functions in both the respiratory and reproductive systems are not fully understood and are still the subject of ongoing research.
Epididymal secretory proteins (ESPs) are a group of proteins that are produced and secreted by the epididymis, a long, coiled tube that lies alongside the testicle in males. The epididymis is responsible for maturing sperm cells after they have been produced in the testes.
The ESPs play a crucial role in this maturation process by interacting with the sperm and promoting their motility, survival, and fertilizing ability. These proteins are thought to protect sperm from damage during their transit through the male reproductive tract and also help to prepare them for fertilization of the egg in the female reproductive tract.
The ESPs include a variety of different protein types, such as enzymes, binding proteins, and structural proteins. Some of the specific ESPs that have been identified and studied include epididymal secretory protein E1 (also known as HE1), epididymal protease inhibitor, and lactoferrin.
Abnormalities in the expression or function of ESPs have been associated with male infertility, highlighting their importance in reproductive health.
Seminal plasma proteins are a group of proteins that are present in the seminal fluid, which is the liquid component of semen. These proteins originate primarily from the accessory sex glands, including the prostate, seminal vesicles, and bulbourethral glands, and play various roles in the maintenance of sperm function and fertility.
Some of the key functions of seminal plasma proteins include:
1. Nutrition: Seminal plasma proteins provide energy sources and essential nutrients to support sperm survival and motility during their journey through the female reproductive tract.
2. Protection: These proteins help protect sperm from oxidative stress, immune attack, and other environmental factors that could negatively impact sperm function or viability.
3. Lubrication: Seminal plasma proteins contribute to the formation of a fluid medium that facilitates the ejaculation and transport of sperm through the female reproductive tract.
4. Coagulation and liquefaction: Some seminal plasma proteins are involved in the initial coagulation and subsequent liquefaction of semen, which helps ensure proper sperm release and distribution during ejaculation.
5. Interaction with female reproductive system: Seminal plasma proteins can interact with components of the female reproductive tract to modulate immune responses, promote implantation, and support early embryonic development.
Examples of seminal plasma proteins include prostate-specific antigen (PSA), prostate-specific acid phosphatase (PSAP), and semenogelins. Abnormal levels or dysfunctions in these proteins have been associated with various reproductive disorders, such as infertility, prostatitis, and prostate cancer.
Salivary proteins and peptides refer to the diverse group of molecules that are present in saliva, which is the clear, slightly alkaline fluid produced by the salivary glands in the mouth. These proteins and peptides play a crucial role in maintaining oral health and contributing to various physiological functions.
Some common types of salivary proteins and peptides include:
1. **Mucins**: These are large, heavily glycosylated proteins that give saliva its viscous quality. They help to lubricate the oral cavity, protect the mucosal surfaces, and aid in food bolus formation.
2. **Amylases**: These enzymes break down carbohydrates into simpler sugars, initiating the digestive process even before food reaches the stomach.
3. **Proline-rich proteins (PRPs)**: PRPs contribute to the buffering capacity of saliva and help protect against tooth erosion by forming a protective layer on tooth enamel.
4. **Histatins**: These are small cationic peptides with antimicrobial properties, playing a significant role in maintaining oral microbial homeostasis and preventing dental caries.
5. **Lactoferrin**: An iron-binding protein that exhibits antibacterial, antifungal, and anti-inflammatory activities, contributing to the overall oral health.
6. **Statherin and Cystatins**: These proteins regulate calcium phosphate precipitation, preventing dental calculus formation and maintaining tooth mineral homeostasis.
Salivary proteins and peptides have attracted significant interest in recent years due to their potential diagnostic and therapeutic applications. Alterations in the composition of these molecules can provide valuable insights into various oral and systemic diseases, making them promising biomarkers for disease detection and monitoring.
A carcinoid tumor is a type of slow-growing neuroendocrine tumor that usually originates in the digestive tract, particularly in the small intestine. These tumors can also arise in other areas such as the lungs, appendix, and rarely in other organs. Carcinoid tumors develop from cells of the diffuse endocrine system (also known as the neuroendocrine system) that are capable of producing hormones or biologically active amines.
Carcinoid tumors can produce and release various hormones and bioactive substances, such as serotonin, histamine, bradykinins, prostaglandins, and tachykinins, which can lead to a variety of symptoms. The most common syndrome associated with carcinoid tumors is the carcinoid syndrome, characterized by flushing, diarrhea, abdominal cramping, and wheezing or difficulty breathing.
Carcinoid tumors are typically classified as functional or nonfunctional based on whether they produce and secrete hormones that cause symptoms. Functional carcinoid tumors account for approximately 30% of cases and can lead to the development of carcinoid syndrome, while nonfunctional tumors do not produce significant amounts of hormones and are often asymptomatic until they grow large enough to cause local or distant complications.
Treatment options for carcinoid tumors depend on the location, size, and extent of the tumor, as well as whether it is functional or nonfunctional. Treatment may include surgery, medications (such as somatostatin analogs, chemotherapy, or targeted therapies), and radiation therapy. Regular follow-up with imaging studies and biochemical tests is essential to monitor for recurrence and assess treatment response.
The endoplasmic reticulum (ER) is a network of interconnected tubules and sacs that are present in the cytoplasm of eukaryotic cells. It is a continuous membranous organelle that plays a crucial role in the synthesis, folding, modification, and transport of proteins and lipids.
The ER has two main types: rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). RER is covered with ribosomes, which give it a rough appearance, and is responsible for protein synthesis. On the other hand, SER lacks ribosomes and is involved in lipid synthesis, drug detoxification, calcium homeostasis, and steroid hormone production.
In summary, the endoplasmic reticulum is a vital organelle that functions in various cellular processes, including protein and lipid metabolism, calcium regulation, and detoxification.
Chromogranin B is a protein that is primarily found in the secretory granules of neuroendocrine cells, including neurons and endocrine cells. These granules are specialized organelles where hormones and neurotransmitters are stored before being released into the extracellular space. Chromogranin B is co-synthesized and packaged with these secretory products and is therefore often used as a marker for neuroendocrine differentiation.
Chromogranin B is a member of the chromogranin/secretogranin family of proteins, which are characterized by their ability to form large aggregates in the acidic environment of secretory granules. These aggregates play a role in the sorting and processing of secretory products, as well as in the regulation of granule biogenesis and exocytosis.
Chromogranin B has been shown to have various biological activities, including inhibition of protein kinase C, stimulation of calmodulin-dependent processes, and modulation of ion channel activity. However, its precise physiological functions remain to be fully elucidated. Dysregulation of chromogranin B expression and processing has been implicated in several pathological conditions, including neurodegenerative diseases and neoplasia.
Chymotrypsinogen is the inactive precursor form of the enzyme chymotrypsin, which is produced in the pancreas and plays a crucial role in digesting proteins in the small intestine. This zymogen is activated when it is cleaved by another protease called trypsin, resulting in the formation of the active enzyme chymotrypsin. Chymotrypsinogen is synthesized and stored in the pancreas as a proenzyme to prevent premature activation and potential damage to the pancreatic tissue. Once released into the small intestine, trypsin-mediated cleavage of chymotrypsinogen leads to the formation of chymotrypsin, which then contributes to protein breakdown and absorption in the gut.
Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.
The Golgi apparatus, also known as the Golgi complex or simply the Golgi, is a membrane-bound organelle found in the cytoplasm of most eukaryotic cells. It plays a crucial role in the processing, sorting, and packaging of proteins and lipids for transport to their final destinations within the cell or for secretion outside the cell.
The Golgi apparatus consists of a series of flattened, disc-shaped sacs called cisternae, which are stacked together in a parallel arrangement. These stacks are often interconnected by tubular structures called tubules or vesicles. The Golgi apparatus has two main faces: the cis face, which is closest to the endoplasmic reticulum (ER) and receives proteins and lipids directly from the ER; and the trans face, which is responsible for sorting and dispatching these molecules to their final destinations.
The Golgi apparatus performs several essential functions in the cell:
1. Protein processing: After proteins are synthesized in the ER, they are transported to the cis face of the Golgi apparatus, where they undergo various post-translational modifications, such as glycosylation (the addition of sugar molecules) and sulfation. These modifications help determine the protein's final structure, function, and targeting.
2. Lipid modification: The Golgi apparatus also modifies lipids by adding or removing different functional groups, which can influence their properties and localization within the cell.
3. Protein sorting and packaging: Once proteins and lipids have been processed, they are sorted and packaged into vesicles at the trans face of the Golgi apparatus. These vesicles then transport their cargo to various destinations, such as lysosomes, plasma membrane, or extracellular space.
4. Intracellular transport: The Golgi apparatus serves as a central hub for intracellular trafficking, coordinating the movement of vesicles and other transport carriers between different organelles and cellular compartments.
5. Cell-cell communication: Some proteins that are processed and packaged in the Golgi apparatus are destined for secretion, playing crucial roles in cell-cell communication and maintaining tissue homeostasis.
In summary, the Golgi apparatus is a vital organelle involved in various cellular processes, including post-translational modification, sorting, packaging, and intracellular transport of proteins and lipids. Its proper functioning is essential for maintaining cellular homeostasis and overall organismal health.
The seminal vesicles are a pair of glands located in the male reproductive system, posterior to the urinary bladder and superior to the prostate gland. They are approximately 5 cm long and have a convoluted structure with many finger-like projections called infoldings. The primary function of seminal vesicles is to produce and secrete a significant portion of the seminal fluid, which makes up the bulk of semen along with spermatozoa from the testes and fluids from the prostate gland and bulbourethral glands.
The secretion of the seminal vesicles is rich in fructose, which serves as an energy source for sperm, as well as various proteins, enzymes, vitamins, and minerals that contribute to maintaining the optimal environment for sperm survival, nourishment, and transport. During sexual arousal and ejaculation, the smooth muscles in the walls of the seminal vesicles contract, forcing the stored secretion into the urethra, where it mixes with other fluids before being expelled from the body as semen.
SCG5
Proprotein convertase 2
Nerve tissue protein
SCG5 - Wikipedia
DeCS
Molecular Chaperones < Proteins << Amino Acid residues <<< Amino Acids @...
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Effect of ACTH on VIP and galanin release from the pituitary. - Oxford Neuroscience
SMN Complex Proteins (medical concept explorer)
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Molecular Chaperones (definition)
Myelin Proteins | Harvard Catalyst Profiles | Harvard Catalyst
Outcomes represent the mean SD, N=3 - Challenges Faced with Small Molecular Modulators of Dehydrogenase Inhibitors
Synaptogyrins | Profiles RNS
Molecular Chaperones | Profiles RNS
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Regulation of Prohormone Convertases in Hypothalamic Neurons - M.MOAM.INFO
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Circulating EM66 is a highly sensitive marker for the diagnosis and follow-up of pheochromocytoma
Pituitary adenylate cyclase-activating polypeptide releases 7B2, adrenocorticotrophin, growth hormone and prolactin from the...
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S100 Proteins | Harvard Catalyst Profiles | Harvard Catalyst
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S100 Proteins | Profiles RNS
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Secretion5
- Doses of ACTH that altered the secretion of VIP and galanin had no effect on 7B2 and substance P release. (ox.ac.uk)
- The ciliary epithelium, a bilayer of secretory neuroepithelial cells, is the site of synthesis of aqueous humor (inflow system), and it regulates its secretion by the coordinated action of a complex transport system that involves ion channels and active transporters. (yale.edu)
- The ocular ciliary epithelium as a novel endocrine secretory epithelium: The secretion of aqueous humor and the regulation of intraocular pressure (IOP) are physiologically and pathophysiologically important processes for the integrity and normal function of the mammalian eye. (yale.edu)
- The ciliary epithelium, a bilayer of secretory neuroepithelial cells, is the site of synthesis of aqueous humor (inflow system), and regulates its secretion by the coordinated action of a complex transport system involving ion channels and active ion secretion, from the stromal to the aqueous-humor surface, followed by osmotic water movement. (yale.edu)
- 3-5 Thisobser- vationcombinedwiththeirubiquitousdistributioninneuroendo- crine,endocrineandnervoustissuesmakesCgsusefulmarkersof secretion of normal and tumoral neuroendocrine cells. (123dok.net)
Synaptic vesicles1
- A subfamily of MARVEL domain-containing proteins that are found in SYNAPTIC VESICLES, where they may play a role in modulating neuronal signaling. (ouhsc.edu)
Intracellular calcium-1
- A family of intracellular calcium-sensing proteins found predominately in NEURONS and PHOTORECEPTOR CELLS . (nih.gov)
Neuronal2
- Neuronal calcium-sensor proteins interact with other regulatory proteins to mediate physiological responses to a change in intracellular calcium concentration. (nih.gov)
- A neuronal protein consisting of three PDZ DOMAINS, an SH3 DOMAIN, and a C-terminal guanylate kinase-like region (see MAGUK PROTEINS). (bvsalud.org)
Polypeptides2
- In protein science , Molecular Chaperones , in our body's cells, are a family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. (wellnessadvantage.com)
- Planning of His-tagged 21-kDa 7B2 and 21 kDa proSAAS and truncated proteins Recombinant His-tagged 21-kDa 7B2 and 7B2 polypeptides 30C150 and 68C150 had been ready using the QIAexpress program (Qiagen). (engineering-gdfsuez.com)
Tissues2
- The protein expressed by this gene is widely distributed in neuroendocrine tissues. (wikipedia.org)
- Chromogranins (Cgs) constitute a family of acidic glycopro- teins encompassing chromogranin A (CgA), chromogranin B (CgB) and secretograninII (SgII) that arewidely distributedin neuroendocrine tissues where they are packaged in secretory gran- ules. (123dok.net)
Aggregation3
- It functions as a chaperone protein for the proprotein convertase PC2 by blocking the aggregation of this protein, and is required for the production of an active PC2 enzyme. (wikipedia.org)
- In our body, Molecular Chaperones are able to inhibit the aggregation of partially denatured proteins and refold them. (wellnessadvantage.com)
- Protein citrullination marks myelin protein aggregation and disease progression in mouse ALS models. (harvard.edu)
Mesh1
- Myelin Proteins" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (harvard.edu)
Predominately1
- A family of homologous proteins of low MOLECULAR WEIGHT that are predominately expressed in the BRAIN and that have been implicated in a variety of human diseases. (nih.gov)
Molecular chaperone2
- An acidic protein found in the NEUROENDOCRINE SYSTEM that functions as a molecular chaperone for PROPROTEIN CONVERTASE 2. (bvsalud.org)
- ApoJ (clusterin) , also known as testosterone repressed prostate message-2, sulfated glycoprotien-2, and Sp-40 and CLU, functions as a secreted molecular chaperone protein , which may have either an intracellular or extracellular function. (wellnessadvantage.com)
Drosophila1
- Interaction of Drosophila melanogaster prohormone convertase 2 and 7B2. (wikipedia.org)
Substance1
- Fractions of 1.5 ml were collected at 3 min intervals and analyzed for vasoactive intestinal peptide (VIP), galanin, 7B2, and substance P, using specific radioimmunoassays. (ox.ac.uk)
Found1
- Proteins found in the myelin sheath. (harvard.edu)
Entry1
- There is a Pfam entry for this protein: Secretogranin_V (PF05281). (wikipedia.org)
Functions1
- 1 The physiologicalrole of these proteins is unclear but a number of potential biological functions have been postulated, including regulationof secretory granule formation and produc- tion ofbioactivepeptidesthroughproteolyticprocessing. (123dok.net)
Cells3
- Expression of circular RNA CDR1-AS in colon cancer cells increases cell surface PD-L1 protein levels. (harvard.edu)
- On the next day, cells had been cleaned with serum-free moderate and treated with either automobile, 21-kDa 7B2 (15 M), 21-kDa proSAAS (15 M), or carbonic anhydrase (5 M) as a poor control, for 48 h. (engineering-gdfsuez.com)
- Neuro2A cells were transfected with vectors encoding rat 21-kDa 7B2 and mouse 27-kDa transiently.ProSAAS and 7B2 might execute a chaperone part while secretory anti-aggregants in regular islet cell function and in type 2 diabetes. (engineering-gdfsuez.com)
Specific1
- In our body, Metallochaperone is a family of soluble metal binding proteins involved in the intracellular transport of specific metal ions and their transfer to the appropriate metalloprotein precursor. (wellnessadvantage.com)
Mouse1
- 21-kDa mouse His-tagged proSAAS (proSAAS 1-180) proteins was ready as Ibodutant (MEN 15596) referred to previously [21]. (engineering-gdfsuez.com)
Central1
- Structure-function research showed a central area within 21-kDa 7B2 can be important with this impact and exposed the need for the N-terminal area of proSAAS. (engineering-gdfsuez.com)
Function2
- It is an intrinsically disordered protein that may also function as a chaperone for other aggregating secretory proteins in addition to proPC2 (Helwig et al. (wikipedia.org)
- ProSAAS and 7B2 may execute a chaperone part as secretory anti-aggregants in regular islet cell function and in type 2 diabetes. (engineering-gdfsuez.com)
Potential1
- Finally, we have examined the potential aftereffect of intracellularly-expressed 7B2 and proSAAS. (engineering-gdfsuez.com)
Chaperone4
- It functions as a chaperone protein for the proprotein convertase PC2 by blocking the aggregation of this protein, and is required for the production of an active PC2 enzyme. (wikipedia.org)
- It is an intrinsically disordered protein that may also function as a chaperone for other aggregating secretory proteins in addition to proPC2 (Helwig et al. (wikipedia.org)
- An acidic protein found in the NEUROENDOCRINE SYSTEM that functions as a molecular chaperone for PROPROTEIN CONVERTASE 2. (bvsalud.org)
- Here, we investigated in detail whether this decreased levels of AVP expression in GC treated patients might be due to the down regulation of the prohormone convertases PC-1 and PC-2, and the molecular chaperone 7B2, as was reported previously in some AVP-related disorders. (nel.edu)
S100 Proteins3
- S100 Proteins" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (harvard.edu)
- This graph shows the total number of publications written about "S100 Proteins" by people in Harvard Catalyst Profiles by year, and whether "S100 Proteins" was a major or minor topic of these publication. (harvard.edu)
- Below are the most recent publications written about "S100 Proteins" by people in Profiles. (harvard.edu)
Pancreatic1
- 5. Expression, intracellular localization, and gene transcription regulation of the secretory protein 7B2 in endocrine pancreatic cell lines and human insulinomas. (nih.gov)
Amino acids1
- 7B2 is a polypeptide of 185 amino acids which is predominantly found in secretory granules and is widely distributed in rat and human tissues. (nih.gov)
Pituitary2
- We investigated the ability of the two forms of PACAP to stimulate GH, prolactin and 7B2 release by the rat pituitary clonal cell line GH3, and ACTH and 7B2 by the mouse pituitary clonal cell line AtT-20. (nih.gov)
- 1. Differential expression of the gene encoding the novel pituitary polypeptide 7B2 in human lung cancer cells. (nih.gov)
Acidic1
- A family of highly acidic calcium-binding proteins found in large concentration in the brain and believed to be glial in origin. (harvard.edu)
Widely distributed1
- The protein expressed by this gene is widely distributed in neuroendocrine tissues. (wikipedia.org)
Gene3
- Neuroendocrine protein 7B2 is a protein that in humans is encoded by the SCG5 gene. (wikipedia.org)
- 19. Protein expression of the RB-related gene family and SV40 large T antigen in mesothelioma and lung cancer. (nih.gov)
- Probe Set ID Ref Seq Protein ID Signal Strength Name Gene Symbol Species Function Swiss-Prot ID Amino Acid Sequence 1367452_at NP_598278 16.8 small ubiquitin-related modifier 2 precursor Sumo2 Rattus norvegicus " Ubiquitin-like protein that can be covalently attached to proteins as a monomer or as a lysine-linked polymer. (nih.gov)
Molecular1
- Proteína ácida que se encuentra en el SISTEMA NEUROENDOCRINO y que funciona como una chaperona molecular para la PROPROTEÍNA-CONVERTASA 2. (bvsalud.org)
MOTIFS1
- They have in common the EF-hand motif (EF HAND MOTIFS) found on a number of calcium binding proteins. (harvard.edu)
Expression4
- 3. Expression of p64c-myc and neuroendocrine properties define three subclasses of small cell lung cancer. (nih.gov)
- 13. Expression of vesicular monoamine transporters, synaptosomal-associated protein 25 and syntaxin1: a signature of human small cell lung carcinoma. (nih.gov)
- An immunocytochemical study was performed on post-mortem hypothalami of GC exposed patients and controls, in which quantification of proAVP, AVP, neurophysin (NP) and oxytocin (OXT) expression were done along with the quantification of PC1, PC2 and 7B2 expression in the paraventricular nucleus, by using a computerized image analysis system. (nel.edu)
- Although in most of the GC treated patients, the expression intensities of PC1 and PC2 were decreased parallel to the decrease in AVP, the mean expression levels of neither of PC1 and PC2, nor of 7B2 were statistically different between the groups (p=0.20-0.80). (nel.edu)
Complex2
- Coatomer complex is required for budding from Golgi membranes, and is essential for the retrograde Golgi-to-ER transport of dilysine-tagged proteins. (nih.gov)
- The ternary complex containing UFD1L, VCP and NPLOC4 binds ubiquitinated proteins and is necessary for the export of misfolded proteins from the ER to the cytoplasm, where they are degraded by the proteasome. (nih.gov)
Found in large1
- A microtubule subunit protein found in large quantities in mammalian brain. (wakehealth.edu)
Human1
- 8. IA-1, a new marker for neuroendocrine differentiation in human lung cancer cell lines. (nih.gov)
Cell2
- 4. A comparison of synaptophysin, chromogranin, and L-dopa decarboxylase as markers for neuroendocrine differentiation in lung cancer cell lines. (nih.gov)
- 18. Quantitative reverse transcription-polymerase chain reaction measurement of HASH1 (ASCL1), a marker for small cell lung carcinomas with neuroendocrine features. (nih.gov)