• guanine nucleo
  • Insulin-like growth factor 1 ( IGF-1 ) signaling promotes activation of Insulin-like growth factor 1 receptor ( IGF-1 receptor ) that forms a complex with Rho guanine nucleotide exchange factor (GEF) 12 ( LARG ) [ 4 ]. (bio-rad.com)
  • In addition, G-protein alpha-12 family can activate RhoA by stimulating Rho guanine nucleotide exchange factor (GEF) 1 ( ARHGEF1(p115RhoGEF) ) [ 11 ], [ 12 ]. (bio-rad.com)
  • RAS guanyl nucleotide-releasing protein (RASGRP) is a member of a family of genes characterized by the presence of a Ras superfamily guanine nucleotide exchange factor (GEF) domain. (wikipedia.org)
  • cytosolic
  • Indeed, Rap1 activation parallels the iloprost- and forskolin-induced Ca 2+ increase and is unaffected by the calcium chelator 1,2-bis(2-aminophenoxy)ethane- N , N , N ′, N ′,-tetraacetic acid-AM. These findings reveal a novel mechanism for elevating cytosolic Ca 2+ by cAMP, possibly via GTP-Rap1. (ahajournals.org)
  • 6 The data show that in addition to MEG-01 cells, human stem cells and immature megakaryocytes respond to iloprost with an increase in cAMP and a rise in [Ca 2+ ] i and that cAMP controls cytosolic Ca 2+ , possibly via Rap1-GTP. (ahajournals.org)
  • Nitrogen Cavitation and Differential Centrifugation Allows for Monitoring the Distribution of Peripheral Membrane Proteins in Cultured Cells Mo Zhou 1 , Mark R. Philips 1 1 Langone Medical Center, New York University Here we present protocols for detergent-free homogenization of cultured mammalian cells based on nitrogen cavitation and subsequent separation of cytosolic and membrane-bound proteins by ultracentrifugation. (jove.com)
  • pathway
  • Genetic interaction experiments show that Rap1 and Cno act in the same molecular pathway during DC and that the function of both molecules in DC depends on their ability to interact. (genetics.org)
  • We further show that Rap1 acts upstream of Cno, but that Rap1, unlike Cno, is not involved in the stimulation of JNK pathway activity, indicating that Cno has both a Rap1-dependent and a Rap1-independent function in the DC process. (genetics.org)
  • Although cAMP elevation did not alter the sensitivity of metastatic melanoma cells to BRAF(V600E) and MEK inhibitors, the EPAC-RAP1 axis appears to contribute to resistance to MAPK pathway inhibition. (aacrjournals.org)
  • The prosurvival mechanism involving the cAMP-EPAC-RAP1 signaling pathway suggest the potential for new targeted therapies in melanoma. (aacrjournals.org)
  • Defining the mechanism for how these proteins function within a given pathway is important in understanding the integration and communication of signalling networks with one another. (biochemj.org)
  • Activation of this pathway is essential to various T-cell processes, including proliferation and differentiation. (biochemj.org)
  • A PLC inhibitor was used to elucidate the mechanism of this Rap activation signalling pathway. (ubc.ca)
  • GAB proteins were one of the first docking proteins identified in the mammalian signal transduction pathway. (wikipedia.org)
  • By binding to the p85 subunit of PI3K, and continuing this signaling pathway GAB provides positive feedback for the creation of PIP3, produced as a result of the PI3K pathway, which binds to GAB2 in the membrane and promotes activation of more PI3Ks. (wikipedia.org)
  • GAB protein binding to SHP2 molecules acts as an activator whose main effect is the activation of the ERK/MAPK pathway. (wikipedia.org)
  • moreover, TNF-α can elevate MAP4K4 expression using transcription factors The JNK pathway is implicated in a number of physiological processes and involves JNKs - kinases responsible for the phosphorylation of a downstream protein called c-Jun. (wikipedia.org)
  • The activation of the JNK signal transduction pathway by MAP4K4 has been implicated in apoptotic regulation of many different cell types, tumorigenesis and/or inflammation. (wikipedia.org)
  • Upon binding, p53 up-regulates MAP4K4 expression leading to the activation of the JNK signaling pathway. (wikipedia.org)
  • Integrin
  • Integrin signaling also induces formation of a complex of p130Cas, the adapter protein Crk, and a third molecule, DOCK 180, that is required for membrane ruffling, a component of cell migration ( 13 , 14 ). (jimmunol.org)
  • The heterotypic platelet-neutrophil interactions are mainly mediated by binding of neutrophil P-selectin glycoprotein ligand-1 (PSGL-1) and αMβ2 integrin to platelet P-selectin and glycoprotein Ibα (GPIbα), respectively [ 8 - 12 ]. (pubmedcentralcanada.ca)
  • In outside-in signalling, integrins transmit signals from the exterior environment to the interior of the cell upon integrin ligand binding. (biochemj.org)
  • Although TCR ESC proteins have been shown to be involved in integrin inside-out signalling mediated by TCR and chemokines, little is known about the role of these proteins in integrin outside-in signalling [ 8 - 10 ]. (biochemj.org)
  • In our previous work, we showed that there is a failure of chemokine-induced polar clustering of this integrin in α4β1 + CLL clones ( 4 ) but did not attempt to further characterize the nature of the defect in activation of αLβ2. (aacrjournals.org)
  • RAPL is also an integrin-associated protein as RAPL polarizes to the immunological synapse following antigen stimulation of T cells, colocalizes with LFA-1 following TCR or chemokine stimulation, and co-immunoprecipitates with LFA-1 in a Rap1-dependent manner (108). (wikipedia.org)
  • This provides a mechanism by which Rap1 can act directly on integrins and modulate integrin affinity and/or clustering. (wikipedia.org)
  • Thus, PKD may play a distinct role in regulating Rap1-dependent integrin regulation. (wikipedia.org)
  • Like RAPL, RIAM interacts preferentially with active Rap1, and overexpression of RIAM enhances integrin-mediated adhesion. (wikipedia.org)
  • There are also, however, other pathways that are activated by this interaction such as the pathways c-Kit-induced Rac activation and β1-integrin. (wikipedia.org)
  • pathways
  • Little is currently known about the signaling pathways mediating the downstream effects of Rap1 in vertebrates or Drosophila. (genetics.org)
  • In mammalian cutaneous melanocytes, cAMP-mediated signaling pathways activated by G-protein-coupled receptors (GPCR), like melanocortin 1 receptor (MC1R), play critical roles in melanocyte homeostasis including cell survival, proliferation, and pigment synthesis. (aacrjournals.org)
  • Distinct signalling pathways producing diverse cellular outcomes can utilize similar subsets of proteins. (biochemj.org)
  • however, these proteins display functionally distinct roles in these pathways. (biochemj.org)
  • however, other receptor pathways on T-cells, including IFNαR (interferon-α receptor) and CXCR4 (CXC chemokine receptor 4), are integrated through the common use of this subset of proteins [ 1 - 7 ]. (biochemj.org)
  • This protein functions as a signal transducer for a wide variety of signaling pathways, including those promoting neural and bone formation as well as tumor growth. (wikipedia.org)
  • LMDs are docking proteins that function as platforms mediating interaction between different signaling pathways and assisting with signal integration. (wikipedia.org)
  • GAB2 mediates the interactions between receptor tyrosine kinases (RTK) or non-RTK receptors, such as G protein coupled receptors, cytokine receptors, multichain immune recognition receptors and integrins, and the molecules of the intracellular signaling pathways. (wikipedia.org)
  • By providing a platform to host a wide array of interactions from extracellular inputs to intracellular pathways, GAB proteins can act as a gatekeeper to the cell, modulating and integrating signals as they pass them along, to control the functional state within the cell. (wikipedia.org)
  • Mutagenesis and Binding assays have helped to identify which molecules and what pathways are downstream of GAB2. (wikipedia.org)
  • The two main pathways of GAB proteins are SHP2 and PI3K. (wikipedia.org)
  • The effects of all the pathways activated by GAB proteins are not known, but it is easy to see that amplification of signal can progress quickly and these proteins can have large effects on the state of the cell. (wikipedia.org)
  • defective rap1
  • While restoration of the intracellular redox balance seems to reverse the hypo responsiveness of the SF T cells, this had no effect on the defective rap1 activation. (bmj.com)
  • superfamily
  • Two classes of cell surface proteins function as receptors for the neurotrophins, the Trk family of receptor tyrosine kinases and the p75 neurotrophin receptor (p75NTR), a member of the TNF receptor superfamily. (sigmaaldrich.com)
  • These proteins are divided into families depending on their protein structure, and the most well studied is the Ras superfamily, of which Rap1 is a member. (wikipedia.org)
  • intracellular
  • Upregulation of intracellular GSH by incubation with 10 mM NAC for 48 h resulted in diminished Rap1 activation, while depletion of GSH by pre-incubation with 200mM BSO resulted in increased Rap1 activation. (bmj.com)
  • The transmembrane and intracellular domain of the p75NTR resembles the mammalian p75-homolog NRH2, the latter that can, like p75NTR, modulate ligand binding to TrkA. (sigmaaldrich.com)
  • Dock4, (Dedicator of cytokinesis 4) also known as DOCK4, is a large (~190 kDa) protein involved in intracellular signalling networks. (wikipedia.org)
  • Dock7 (Dedicator of cytokinesis 7), also known as Zir2, is a large (~240 kDa) protein involved in intracellular signalling networks. (wikipedia.org)
  • The PH domain of GAB2 recognizes phosphatidylinositol 3,4,5-triphosphate(PIP3) in the membrane and is responsible for localizing the GAB protein on the intracellular surface of the membrane and in regions where the cell contacts another cell. (wikipedia.org)
  • plasma membrane
  • While Ras is mainly localized at the plasma membrane, Rap1 has been found in different membrane compartments, depending on the cell type. (genetics.org)
  • In addition, knockdown of RIAM inhibits adhesion induced by active Rap1 and inhibits the localization of active Rap1 at the plasma membrane. (wikipedia.org)
  • Dock4 also contains a DHR2 domain (also known as Docker2 or CZH2) which is conserved among DOCK family proteins and mediates GEF-dependent functions, and a DHR1 domain (CZH1/Docker1) which has been shown to bind PtdIns(3,4,5)P3, an important step in recruitment to the plasma membrane. (wikipedia.org)
  • ELMO also binds the activated form of the small G protein RhoG and this has been shown to promote DOCK-dependent signalling by helping recruit the ELMO-DOCK complex to areas of high substrate availability (usually the plasma membrane). (wikipedia.org)
  • adhesion
  • More recently, Rap1 has been shown to play a role in cell adhesion, specifically in the positioning of adherens junctions in proliferating epithelial cells ( K nox and B rown 2002 ). (genetics.org)
  • AND-34 binds by its GDP exchange factor domain to the C terminus of HEF1, a region of HEF1 previously implicated in apoptotic, adhesion, and cell cycle-regulated signaling. (jimmunol.org)
  • While neutrophils attach to the inflamed venules under low blood shear, platelets adhere to activated ECs and sub-endothelial matrix proteins such as collagen and von Willebrand factor (vWF) under high blood shear and then support neutrophil rolling and adhesion as well as platelet accumulation following arterial injury [ 13 - 15 ]. (pubmedcentralcanada.ca)
  • Despite the similarities, the functions of Rap1 and Rap2 have not been completely elucidated although recent studies suggest that both Rap proteins may be involved in cell migration and adhesion. (ubc.ca)
  • CD11a/18) integrins, and ligand binding]to VCAM-1 and intercellular adhesion molecule-1 (ICAM-1), respectively]. (aacrjournals.org)
  • Whereas Ras is known for its role in cell proliferation and survival, Rap1 is predominantly involved in cell adhesion and cell junction formation. (wikipedia.org)
  • TCR-mediated activation of Mst1 is dependent on RAPL, and TCR-mediated adhesion to ICAM-1 and antigen-dependent conjugate formation are impaired following RNAi-mediated knockdown of Mst1 expression. (wikipedia.org)
  • Accordingly, cellular depletion of RanBP2 releases Epac1 from the NPC and enhances cAMP-induced Rap activation and cell adhesion. (rupress.org)
  • interaction
  • Below are the list of possible Krev interaction trapped protein products. (mybiosource.com)
  • Also known as Krev interaction trapped protein 1 (Krev interaction trapped 1) (Cerebral cavernous malformations 1 protein homolog). (mybiosource.com)
  • Binding to ELMO requires the atypical PH domain of ELMO and also involves an interaction between the N-terminal SH3 domain of DOCK and a proline-rich motif at the ELMO C-terminus. (wikipedia.org)
  • In Schwann cells Dock7 was shown to regulate the activation of Cdc42 as well as Rac1 however no direct interaction between Dock7 and Cdc42 has been demonstrated. (wikipedia.org)
  • RAP1B
  • Acts in concert with CDH5 to establish and maintain correct endothelial cell polarity and vascular lumen and these effects are mediated by recruitment and activation of the Par polarity complex and RAP1B. (mybiosource.com)
  • effectors
  • Of the two states M-Ras can switch between, M-Ras is predominantly found in its state 1 conformation, which does not bind Ras effectors. (wikipedia.org)
  • regulation
  • Loss-of-function (lof) mutations in Drosophila Rap1 cause severe morphogenetic abnormalities during embryonic development, while cell proliferation and cell fate determination, processes that rely heavily on regulation by Ras, appear to be unaffected. (genetics.org)
  • Similarly to many other MAPKKKs, c-Raf is a multidomain protein, with several additional domains to aid the regulation of its catalytic activity. (wikipedia.org)
  • phosphorylation
  • Synovial fluid (SF) T cells from patients with rheumatoid arthritis (RA) display a defective phosphorylation pattern of several pivotal signalling proteins and severe hyporesponsiveness upon antigenic stimulation. (bmj.com)
  • Promotes AKT phosphorylation in a NOTCH-dependent and independent manner, and inhibits ERK1/2 phosphorylation indirectly through activation of the DELTA-NOTCH cascade. (mybiosource.com)
  • It is on the C-terminal tail that the various conserved protein binding motifs and phosphorylation sites of GAB2 are found. (wikipedia.org)
  • Secondary sites also require phosphorylation for the enzyme to assume full activation and is achieved via autophosphorylation or by upstream kinases. (wikipedia.org)
  • receptors
  • Previous work has shown that Rap1 is activated by many receptors. (ubc.ca)
  • Co-expression of p75NTR and Trk also provides more specificity for neurotrophin binding to Trk receptors. (sigmaaldrich.com)
  • In addition to activation by neurotrophins, Trk can be activated by ligands of G-protein coupled receptors, including pituitary adenylate cyclase-activating protein (PACAP) and adenosine A2A. (sigmaaldrich.com)
  • Binding of two NGF molecules induces dimerization of Trk receptors. (sigmaaldrich.com)
  • Neurotrophins induce very different effects depending upon the cell type they bind to, as well as which receptor or complex of receptors are engaged. (sigmaaldrich.com)
  • Rac1
  • Activated Ras-related C3 botulinum toxin substrate 1 ( Rac1 ) by stimulation MCF.2 cell line derived transforming sequence-like ( DBS ) activity promotes RhoA activation [ 14 ], [ 15 ]. (bio-rad.com)
  • Overexpression of DOCK 180 induces activation of Rac, and DOCK 180 binds to Rac1, but not RhoA or Cdc42 ( 15 ). (jimmunol.org)
  • A study of Dock7 in HEK 293 cells and hippocampal neurons has shown that it can bind and promote nucleotide exchange on the Rac subfamily isoforms Rac1 and Rac3. (wikipedia.org)
  • 2002
  • 0\QQa The U n i v e r s i t y o f B r i t i s h Vancouver, Canada & XrnfTt O O p l Columbia http://www.library.ubc.ca/spcoll/thesauth.html 8/15/2002 ABSTRACT Ras and members of the Ras-related family of small GTP-binding proteins are involved in many biological functions. (ubc.ca)
  • isoforms
  • While the biological significance of these isoforms remains to be determined, it can be speculated that such variations alter and determine MAP4K4's interactions with other proteins and factors, ultimately leading to the activation/inhibition of different biochemical and physiological cascades. (wikipedia.org)
  • modulate
  • Rho GDP dissociation inhibitors (GDIs) alpha, beta and gamma ( RhoGDI alpha , LyGDI , and RhoGDI gamma ) bind to RhoA and negatively modulate its activation. (bio-rad.com)
  • Moreover, M-Ras plays a crucial role in the downregulation of OCT4 and NANOG protein levels upon differentiation and has been demonstrated to modulate cell fate at early steps of development during neurogenesis. (wikipedia.org)
  • stimulation
  • The signalling events immediately following TCR stimulation are well characterized and involve the recruitment and assembly of a complex of proteins known as the TCR ESC (early signalling complex). (biochemj.org)
  • In our laboratory, we showed that Rap1 was activated by BCR cross-linking and CXCR4 stimulation. (ubc.ca)
  • Subsequently, this binding and both VEGF and chemokine stimulation are all needed for αLβ2 activation for motility and TEM. (aacrjournals.org)
  • molecules
  • Cno binds to the activated form of Rap1 in a yeast two-hybrid assay, the two molecules colocalize to the adherens junction, and they display very similar phenotypes in embryonic dorsal closure (DC), a process that relies on the elongation and migration of epithelial cell sheets. (genetics.org)
  • to date, none of these molecules have been shown to act as Rap1 targets in an in vivo context. (genetics.org)
  • p75NTR mediates signaling of the myelin-associated and growth inhibitory molecules MAG, Nogo-66 and OMgp though association with the Nogo-receptor and the transmembrane protein LINGO-1. (sigmaaldrich.com)
  • GAB2 is a docking protein with a conserved, folded PH domain attached to the membrane and a large disordered region, which hosts interactions with signaling molecules. (wikipedia.org)
  • Adjacent to the PH domain is a central, proline-rich domain that contains many PXXP motifs for binding to the SH3 domains of signaling molecules such as Grb2 (from which the name "Grb2-associated binding" protein, GAB, comes). (wikipedia.org)
  • GAB2 binds to the SH2 domains of such signaling molecules as SHP2 and PI3K. (wikipedia.org)
  • This would assist in promoting interactions between molecules bound to GAB and resisting degradation. (wikipedia.org)
  • membrane
  • This method is ideal for monitoring the partitioning of peripheral membrane proteins between soluble and membrane fractions. (jove.com)
  • mammalian
  • Here, we demonstrate that Canoe (Cno), the Drosophila homolog of mammalian junctional protein AF-6, acts as an effector of Rap1 in vivo . (genetics.org)
  • In mammalian melanocytes, the cAMP signaling cascade is activated by the binding of α-melanocyte stimulating hormone to melanocortin 1 receptor (MC1R, a GPCR) leading to the expression of micropthalmia-associated transcription factor (MITF), the melanocyte master regulator ( 1 ). (aacrjournals.org)
  • Dock4, however, contains a unique set of motifs at its proline-rich C-terminus which include a Src-binding site that is shared with CED-5, the C. elegans ortholog of mammalian DOCK proteins. (wikipedia.org)
  • vitro
  • RanBP2 inhibits the catalytic activity of Epac1 in vitro by binding to its catalytic CDC25 homology domain. (rupress.org)
  • multidomain
  • The multidomain structure of RanBP2 ( Fig. 1 A ) suggested a more pleiotropic function for this nucleoporin, and RanBP2 is now recognized as a regulator of various proteins that each associate with a selective domain of RanBP2. (rupress.org)
  • platelets
  • Earlier studies have shown that megakaryoblastic cell lines express the prostacyclin receptor 5 Rap1 6 and the 97-kDa sarco/endoplasmic reticulum Ca 2+ -ATPase SERCA3b, which functions in Ca 2+ sequestration in platelets. (ahajournals.org)
  • nucleotide exchange
  • DOCK family proteins are inefficient at promoting nucleotide exchange on their own since they appear to adopt an autoinhibitory conformation in their resting state. (wikipedia.org)
  • It functions as a diacylglycerol (DAG)-regulated nucleotide exchange factor specifically activating Ras through the exchange of bound GDP for GTP. (wikipedia.org)
  • induce
  • Significantly, p130Cas promotes cell migration in a process dependent on Rac but not Ras, although the precise mechanism by which p130Cas complexes induce Rac activation remains unclear ( 16 ). (jimmunol.org)
  • family of proteins
  • The neurotrophins are a family of proteins that regulate cell survival, differentiation and growth in the vertebrate nervous system. (sigmaaldrich.com)
  • The N-terminal is characterized by a Pleckstrin Homology (PH) domain that is the most highly conserved region between all members of the GAB family of proteins. (wikipedia.org)
  • molecular
  • In Drosophila, Rap1 plays a critical role in many different morphogenetic processes, but the molecular mechanisms executing its function are unknown. (genetics.org)