scholarly journals Role of FGD1, a Cdc42 Guanine Nucleotide Exchange Factor, in Epidermal Growth Factor-Stimulated c-Jun NH2-Terminal Kinase Activation and Cell Migration

2011 ◽  
Vol 34 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Toshiyuki Oshima ◽  
Tomofumi Fujino ◽  
Ken Ando ◽  
Makio Hayakawa
Keyword(s):  
Cell Migration ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Kinase Activation ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor ◽  
Epidermal Growth

scholarly journals Ras activation by insulin and epidermal growth factor through enhanced exchange of guanine nucleotides on p21ras

1993 ◽  
Vol 13 (1) ◽  
pp. 155-162
Author(s):  
R H Medema ◽  
A M de Vries-Smits ◽  
G C van der Zon ◽  
J A Maassen ◽  
J L Bos
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Guanine Nucleotide Exchange Factor ◽  
Nucleotide Binding ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Exchange Factor ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor ◽  
Epidermal Growth

A number of growth factors, including insulin and epidermal growth factor (EGF), induce accumulation of the GTP-bound form of p21ras. This accumulation could be caused either by an increase in guanine nucleotide exchange on p21ras or by a decrease in the GTPase activity of p21ras. To investigate whether insulin and EGF affect nucleotide exchange on p21ras, we measured binding of [alpha-32P]GTP to p21ras in cells permeabilized with streptolysin O. For this purpose, we used a cell line which expressed elevated levels of p21 H-ras and which was highly responsive to insulin and EGF. Stimulation with insulin or EGF resulted in an increase in the rate of nucleotide binding to p21ras. To determine whether this increased binding rate is due to the activation of a guanine nucleotide exchange factor, we made use of the inhibitory properties of a dominant negative mutant of p21ras, p21ras (Asn-17). Activation of p21ras by insulin and EGF in intact cells was abolished in cells infected with a recombinant vaccinia virus expressing p21ras (Asn-17). In addition, the enhanced nucleotide binding to p21ras in response to insulin and EGF in permeabilized cells was blocked upon expression of p21ras (Asn-17). From these data, we conclude that the activation of a guanine nucleotide exchange factor is involved in insulin- and EGF-induced activation of p21ras.

scholarly journals Ras activation by insulin and epidermal growth factor through enhanced exchange of guanine nucleotides on p21ras.

1993 ◽  
Vol 13 (1) ◽  
pp. 155-162 ◽  
Author(s):  
R H Medema ◽  
A M de Vries-Smits ◽  
G C van der Zon ◽  
J A Maassen ◽  
J L Bos
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Guanine Nucleotide Exchange Factor ◽  
Nucleotide Binding ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Exchange Factor ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor ◽  
Epidermal Growth

A number of growth factors, including insulin and epidermal growth factor (EGF), induce accumulation of the GTP-bound form of p21ras. This accumulation could be caused either by an increase in guanine nucleotide exchange on p21ras or by a decrease in the GTPase activity of p21ras. To investigate whether insulin and EGF affect nucleotide exchange on p21ras, we measured binding of [alpha-32P]GTP to p21ras in cells permeabilized with streptolysin O. For this purpose, we used a cell line which expressed elevated levels of p21 H-ras and which was highly responsive to insulin and EGF. Stimulation with insulin or EGF resulted in an increase in the rate of nucleotide binding to p21ras. To determine whether this increased binding rate is due to the activation of a guanine nucleotide exchange factor, we made use of the inhibitory properties of a dominant negative mutant of p21ras, p21ras (Asn-17). Activation of p21ras by insulin and EGF in intact cells was abolished in cells infected with a recombinant vaccinia virus expressing p21ras (Asn-17). In addition, the enhanced nucleotide binding to p21ras in response to insulin and EGF in permeabilized cells was blocked upon expression of p21ras (Asn-17). From these data, we conclude that the activation of a guanine nucleotide exchange factor is involved in insulin- and EGF-induced activation of p21ras.

scholarly journals Endogenous RhoG Is Rapidly Activated after Epidermal Growth Factor Stimulation through Multiple Guanine-Nucleotide Exchange Factors

2010 ◽  
Vol 21 (9) ◽  
pp. 1629-1642 ◽  
Author(s):  
Thomas Samson ◽  
Christopher Welch ◽  
Elizabeth Monaghan-Benson ◽  
Klaus M. Hahn ◽  
Keith Burridge
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Guanine Nucleotide Exchange Factors ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors ◽  
Epidermal Growth ◽  
Rapid Activation

RhoG is a member of the Rac-like subgroup of Rho GTPases and has been linked to a variety of different cellular functions. Nevertheless, many aspects of RhoG upstream and downstream signaling remain unclear; in particular, few extracellular stimuli that modulate RhoG activity have been identified. Here, we describe that stimulation of epithelial cells with epidermal growth factor leads to strong and rapid activation of RhoG. Importantly, this rapid activation was not observed with other growth factors tested. The kinetics of RhoG activation after epidermal growth factor (EGF) stimulation parallel the previously described Rac1 activation. However, we show that both GTPases are activated independently of one another. Kinase inhibition studies indicate that the rapid activation of RhoG and Rac1 after EGF treatment requires the activity of the EGF receptor kinase, but neither phosphatidylinositol 3-kinase nor Src kinases. By using nucleotide-free RhoG pull-down assays and small interfering RNA-mediated knockdown studies, we further show that guanine-nucleotide exchange factors (GEFs) of the Vav family mediate EGF-induced rapid activation of RhoG. In addition, we found that in certain cell types the recently described RhoG GEF PLEKHG6 can also contribute to the rapid activation of RhoG after EGF stimulation. Finally, we present results that show that RhoG has functions in EGF-stimulated cell migration and in regulating EGF receptor internalization.

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