Loading...
  • cytoskeleton
  • Dock4 dependent Rac activation regulates reorganisation of the cytoskeleton and leads to the formation of membrane protrusions (e.g. lamellipodia) which are a crucial step in neuronal development and cell migration. (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)
  • 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)
  • 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)
  • 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)
  • 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)
  • 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)
  • actin
  • Mitra A, Radha V. F-actin-binding domain of c-Abl regulates localized phosphorylation of C3G: role of C3G in c-Abl-mediated cell death. (springer.com)
  • regulates
  • Cyclic AMP (cAMP) signaling, triggered by the activation of stimulatory G-protein-coupled receptors (GPCR), regulates a wide range of physiologic functions. (aacrjournals.org)
  • It also implies the existence of Mst1-independent mechanisms by which Rap1 regulates LFA-1 affinity. (wikipedia.org)
  • The protein regulates lymphocyte adhesion and suppresses cell growth in response to activated Rap1 or Ras. (wikipedia.org)
  • superfamily
  • 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)
  • 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)
  • 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)
  • 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)
  • 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)
  • 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)
  • activate
  • 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)
  • The second objective was to uncover how BCR cross-linking and CXCR4 activate Rap proteins. (ubc.ca)
  • First I showed that anti-Ig antibodies, stromal cell-derived factor-1 (SDF-1), and phorbol 12,13-dibutyrate (PdBu) all activate Rap2 in B cells with activation kinetics similar to that for Rap1. (ubc.ca)
  • Interestingly, Dock4 has also been shown to activate Rap1, a feature not reported in any of the other DOCK family proteins to date. (wikipedia.org)
  • For instance, it is activated by Ras guanine nucleotide exchange factors and can bind/activate some Ras protein effectors. (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)
  • 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)
  • In addition, knockdown of RIAM inhibits adhesion induced by active Rap1 and inhibits the localization of active Rap1 at the plasma membrane. (wikipedia.org)
  • interaction
  • Pkp3-Rap1 complex is required for maintaining physical interaction between Rap1 and E-cad. (nih.gov)
  • Note that E-cad loss does not interfere with the interaction between Pkp3, Rap1, and EPAC. (nih.gov)
  • E-cad knockdown did not have the same disruptive effect on Pkp3-Rap1 interaction or the interaction between Rap1 and its main activator, EPAC, suggesting that Pkp3 is required for Rap1 interaction with E-cad, but E-cad is not required for Pkp3-Rap1 interaction (Figure 7D). (nih.gov)
  • 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)
  • LMDs are docking proteins that function as platforms mediating interaction between different signaling pathways and assisting with signal integration. (wikipedia.org)
  • Cdc42
  • Involvement of the c-Src-Crk-C3G-Rap1 signaling in the nectin-induced activation of Cdc42 and formation of adherens junctions. (springer.com)
  • DOCK family proteins contribute to cell signalling by activating G proteins of the Rho family, such as Rac and Cdc42. (wikipedia.org)
  • However, the specificity of the Dock7 DHR2 domain appears to resemble that of DOCK-A/B subfamily proteins in that it binds Rac but not Cdc42. (wikipedia.org)
  • 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)
  • 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)
  • 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)
  • 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)
  • Amplification, up-regulation and over-expression of C3G (CRK SH3 domain-binding guanine nucleotide-releasing factor) in non-small cell lung cancers. (springer.com)
  • 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)
  • upstream
  • In the second part of this manuscript, we show that phospholipase Cε (PLCε) is required for the acrosome reaction downstream of Rap1 and upstream of intra-acrosomal calcium mobilization. (nih.gov)
  • Secondary sites also require phosphorylation for the enzyme to assume full activation and is achieved via autophosphorylation or by upstream kinases. (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)
  • phosphorylation
  • In this case, methylation at lysine 9 on H3 (a mark of transcriptional repression) and phosphorylation at serine 10 on H3 repress each other, whereas phosphorylation at serine 10 enhances acetylation on lysine 14 (a mark of transcriptional activation. (nih.gov)
  • 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)
  • Activation of C3G guanine nucleotide exchange factor for Rap1 by phosphorylation of tyrosine 504. (springer.com)
  • It is on the C-terminal tail that the various conserved protein binding motifs and phosphorylation sites of GAB2 are found. (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)
  • 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)
  • 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)
  • scaffold
  • 2013). In the absence of EPAC activity, E-cad is excluded from a complex that still contains Pkp3 and Rap1, supporting the idea that Pkp3 provides a scaffold for binding and activation of Rap1 required for E-cad association (Figure 7E). (nih.gov)
  • mammalian
  • 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)
  • 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)
  • membrane
  • This method is ideal for monitoring the partitioning of peripheral membrane proteins between soluble and membrane fractions. (jove.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)
  • 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)
  • mapk
  • Identification of the mechanisms regulating the differential activation of the mapk cascade by epidermal growth factor and nerve growth factor in PC12 cells. (springer.com)
  • modulate
  • 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)
  • nucleotide exchange
  • 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)
  • Knudsen BS, Feller SM, Hanafusa H. Four proline-rich sequences of the guanine-nucleotide exchange factor C3G bind with unique specificity to the first Src homology 3 domain of Crk. (springer.com)
  • 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)
  • 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)
  • 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)
  • molecular
  • In Drosophila, Rap1 plays a critical role in many different morphogenetic processes, but the molecular mechanisms executing its function are unknown. (genetics.org)
  • mechanism
  • 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)
  • DOCK
  • Dock7 was identified as one of a number of proteins which share high sequence similarity with the previously described protein Dock180, the archetypal member of the DOCK family. (wikipedia.org)
  • Many DOCK family proteins contain important structural features at their N- and C-termini, however, these regions in Dock7 are poorly characterised thus far and no such features have been identified. (wikipedia.org)
  • Many members of the DOCK family are regulated by protein-protein interactions mediated via domains at their N- and C-termini, however, the mechanisms by which Dock7 is regulated are largely unknown. (wikipedia.org)
  • This observation is consistent with the role of the DHR1 domain in other DOCK family proteins. (wikipedia.org)
  • This apparent promiscuity among DOCK proteins and their targets, coupled with the fact that Rheb is highly expressed in the brain means that Dock7 GEF activity towards Rheb, although not yet demonstrated, would not be surprising. (wikipedia.org)