P-REX2, a novel PI-3-kinase sensitive Rac exchange factor.
We have identified an activator of Rac, P-REX2, that is structurally related to the exchange factor PtdIns(3,4,5)-dependent Rac exchanger (P-REX1), but exhibits distinct tissue-specific expression. P-REX2 is spliced into two RNA species, approximately 3.5 and approximately 10 kb in size. The cDNA corresponding to the smaller transcript encodes a protein that exhibits strong similarity with P-REX1 within its N-terminal domains, but differs in the C-terminal region. P-REX2 promoted increased levels of GTP-bound Rac that could be further stimulated by enhancing PI-3K activity. Thus, P-REX2 may serve as a novel link between Rac activation and the PI-3 kinase pathway.
Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, DHHS, Bethesda, MD 20892-4330, USA.
Hans
H
Rosenfeldt
José
J
Vázquez-Prado
J Silvio
JS
Gutkind
D000595:Amino Acid Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D019295:Computational Biology; D005333:Fetus; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D017930:Genes, Reporter; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007668:Kidney; D008156:Luciferases / Q000235:genetics; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D014176:Protein Biosynthesis; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D020744:rac GTP-Binding Proteins / Q000378:metabolism*
D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; C453280:PREX1 protein, human; C490712:PREX2 protein, human; D011994:Recombinant Proteins; D008156:Luciferases; D019869:Phosphatidylinositol 3-Kinases; D020744:rac GTP-Binding Proteins