Phospholipase C-gamma1: a phospholipase and guanine nucleotide exchange factor.
Although phospholipase C-gamma (PLC-gamma) participates in cellular mitogenesis, evidence indicates that the catalytic activity of PLC-gamma (to hydrolyze certain phosphoinositides) is nonessential to the process. So how is it that PLC-gamma is necessary but its lipase activity is not? Recently published results from Snyder and colleagues describe the ability of PLC-gamma to facilitate guanine nucleotide exchange for the recently identified nucleus-localized GTPase PIKE, which acts to enhance the enzymatic activity of phosphatidylinositol 3'-kinase (PI3K). The authors contend that the SH3 domain, rather than the catalytic domain, of PLC-gamma is required for aiding PIKE, and furthermore, that the mitogenic activity of PLC-gamma depends not on its phospholipase activity, but rather on its interaction with PIKE. Wang and Moran examine the results and piece together a picture of how PLC-gamma cooperates with PIKE.
Wang
Zhixiang
Z
Department of Cell Biology and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada.
Moran
Michael F
MF
D000818:Animals; D002455:Cell Division / Q000502:physiology; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006801:Humans; D020932:Nerve Growth Factor / Q000494:pharmacology; D051966:Phospholipase C gamma; D010738:Type C Phospholipases / Q000187:drug effects / Q000378:metabolism*; D018909:src Homology Domains
D020662:Guanine Nucleotide Exchange Factors; D020932:Nerve Growth Factor; D010738:Type C Phospholipases; D051966:Phospholipase C gamma