P-Rex2, a new guanine-nucleotide exchange factor for Rac.
We have identified a new guanine-nucleotide exchange factor, P-Rex2, and cloned it from human skeletal muscle and brain libraries. It has widespread tissue distribution but is not expressed in neutrophils. P-Rex2 is a 183 kDa protein that activates the small GTPase Rac and is regulated by phosphatidylinositol (3,4,5)-trisphosphate and the beta gamma subunits of heterotrimeric G proteins in vitro and in vivo. P-Rex2 has structure, activity and regulatory properties similar to P-Rex1 but has divergent tissue distribution, as P-Rex1 is mainly expressed in neutrophils. Together, they form an enzyme family capable of mediating Rac signalling downstream of G protein-coupled receptors and phosphoinositide 3-kinase.
Donald
Sarah
S
Signalling Programme, Inositide Laboratory, The Babraham Institute, Babraham, Cambridge CB2 4AT, UK.
Hill
Kirsti
K
Lecureuil
Charlotte
C
Barnouin
Romain
R
Krugmann
Sonja
S
John Coadwell
W
W
Andrews
Simon R
SR
Walker
Simon A
SA
Hawkins
Phillip T
PT
Stephens
Len R
LR
Welch
Heidi C E
HC
D015152:Blotting, Northern; D003001:Cloning, Molecular; D015723:Gene Library; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D009928:Organ Specificity; D021122:Protein Subunits / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
D021122:Protein Subunits; D011994:Recombinant Proteins; D015544:Inositol 1,4,5-Trisphosphate; D020962:Heterotrimeric GTP-Binding Proteins; D020744:rac GTP-Binding Proteins