scholarly journals The Rho Guanine Nucleotide Exchange Factor Syx Regulates the Balance of Dia and ROCK Activities To Promote Polarized-Cancer-Cell Migration

2013 ◽  
Vol 33 (24) ◽  
pp. 4909-4918 ◽  
Author(s):  
J. C. Dachsel ◽  
S. P. Ngok ◽  
L. J. Lewis-Tuffin ◽  
A. Kourtidis ◽  
R. Geyer ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cancer Cell ◽  
Guanine Nucleotide Exchange Factor ◽  
Cancer Cell Migration ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Exchange Factor ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor

scholarly journals The guanine nucleotide exchange factor VAV3 participates in ERBB4-mediated cancer cell migration

2020 ◽  
Vol 295 (33) ◽  
pp. 11559-11571
Author(s):  
Veera K. Ojala ◽  
Anna M. Knittle ◽  
Peppi Kirjalainen ◽  
Johannes A. M. Merilahti ◽  
Maarit Kortesoja ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Breast Cancer Cells ◽  
Guanine Nucleotide Exchange Factor ◽  
Cancer Cell Migration ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Exchange Factor ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor

ERBB4 is a member of the epidermal growth factor receptor (EGFR)/ERBB subfamily of receptor tyrosine kinases that regulates cellular processes including proliferation, migration, and survival. ERBB4 signaling is involved in embryogenesis and homeostasis of healthy adult tissues, but also in human pathologies such as cancer, neurological disorders, and cardiovascular diseases. Here, an MS-based analysis revealed the Vav guanine nucleotide exchange factor 3 (VAV3), an activator of Rho family GTPases, as a critical ERBB4-interacting protein in breast cancer cells. We confirmed the ERBB4–VAV3 interaction by targeted MS and coimmunoprecipitation experiments and further defined it by demonstrating that kinase activity and Tyr-1022 and Tyr-1162 of ERBB4, as well as the intact phosphotyrosine-interacting SH2 domain of VAV3, are necessary for this interaction. We found that ERBB4 stimulates tyrosine phosphorylation of the VAV3 activation domain, known to be required for guanine nucleotide exchange factor (GEF) activity of VAV proteins. In addition to VAV3, the other members of the VAV family, VAV1 and VAV2, also coprecipitated with ERBB4. Analyses of the effects of overexpression of dominant-negative VAV3 constructs or shRNA-mediated down-regulation of VAV3 expression in breast cancer cells indicated that active VAV3 is involved in ERBB4-stimulated cell migration. These results define the VAV GEFs as effectors of ERBB4 activity in a signaling pathway relevant for cancer cell migration.

Trio amino-terminal guanine nucleotide exchange factor domain expression promotes actin cytoskeleton reorganization, cell migration and anchorage-independent cell growth

1999 ◽  
Vol 112 (12) ◽  
pp. 1825-1834 ◽  
Author(s):  
K. Seipel ◽  
Q.G. Medley ◽  
N.L. Kedersha ◽  
X.A. Zhang ◽  
S.P. O'Brien ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Growth ◽  
Actin Cytoskeleton ◽  
Guanine Nucleotide Exchange Factor ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Exchange Factor ◽  
Amino Terminal ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor

Rho family GTPases regulate diverse cellular processes, including extracellular signal-mediated actin cytoskeleton reorganization and cell growth. The functions of GTPases are positively regulated by guanine nucleotide exchange factors, which promote the exchange of GDP for GTP. Trio is a complex protein possessing two guanine nucleotide exchange factor domains, each with adjacent pleckstrin homology and SH3 domains, a protein serine/threonine kinase domain with an adjacent immunoglobulin-like domain and multiple spectrin-like domains. To assess the functional role of the two Trio guanine nucleotide exchange factor domains, NIH 3T3 cell lines stably expressing the individual guanine nucleotide exchange factor domains were established and characterized. Expression of the amino-terminal guanine nucleotide exchange factor domain results in prominent membrane ruffling, whereas cells expressing the carboxy-terminal guanine nucleotide exchange factor domain have lamellae that terminate in miniruffles. Moreover, cells expressing the amino-terminal guanine nucleotide exchange factor domain display more rapid cell spreading, haptotactic cell migration and anchorage-independent growth, suggesting that Trio regulates both cell motility and cell growth. Expression of full-length Trio in COS cells also alters actin cytoskeleton organization, as well as the distribution of focal contact sites. These findings support a role for Trio as a multifunctional protein that integrates and amplifies signals involved in coordinating actin remodeling, which is necessary for cell migration and growth.

scholarly journals Guanine Nucleotide Exchange Factor-H1 Regulates Cell Migration via Localized Activation of RhoA at the Leading Edge

2009 ◽  
Vol 20 (18) ◽  
pp. 4070-4082 ◽  
Author(s):  
Perihan Nalbant ◽  
Yuan-Chen Chang ◽  
Jörg Birkenfeld ◽  
Zee-Fen Chang ◽  
Gary M. Bokoch
Keyword(s):  
Cell Migration ◽  
Focal Adhesion ◽  
Leading Edge ◽  
Guanine Nucleotide Exchange Factor ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Exchange Factor ◽  
Rhoa Activity ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor

Cell migration involves the cooperative reorganization of the actin and microtubule cytoskeletons, as well as the turnover of cell–substrate adhesions, under the control of Rho family GTPases. RhoA is activated at the leading edge of motile cells by unknown mechanisms to control actin stress fiber assembly, contractility, and focal adhesion dynamics. The microtubule-associated guanine nucleotide exchange factor (GEF)-H1 activates RhoA when released from microtubules to initiate a RhoA/Rho kinase/myosin light chain signaling pathway that regulates cellular contractility. However, the contributions of activated GEF-H1 to coordination of cytoskeletal dynamics during cell migration are unknown. We show that small interfering RNA-induced GEF-H1 depletion leads to decreased HeLa cell directional migration due to the loss of the Rho exchange activity of GEF-H1. Analysis of RhoA activity by using a live cell biosensor revealed that GEF-H1 controls localized activation of RhoA at the leading edge. The loss of GEF-H1 is associated with altered leading edge actin dynamics, as well as increased focal adhesion lifetimes. Tyrosine phosphorylation of focal adhesion kinase and paxillin at residues critical for the regulation of focal adhesion dynamics was diminished in the absence of GEF-H1/RhoA signaling. This study establishes GEF-H1 as a critical organizer of key structural and signaling components of cell migration through the localized regulation of RhoA activity at the cell leading edge.

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