Sci. STKE, 5 February 2002
Cell Proliferation PLC-1 "sPIKES" PI3K Activity
The phosphatidylinositol 3-kinase (PI3K) enhancer (PIKE) is small guanosine triphosphatase (GTPase) that associates with nuclear-localized PI3K and increases its lipid kinase activity and its ability to promote cellular proliferation. Activated phospholipase C-1 (PLC-1) can also promote mitogenesis, but this effect does not require the phospholipase activity of PLC-1. Now Ye et al. have found that PLC-1 might act as a guanine nucleotide exchange factor (GEF) for PIKE. The Src homology 3 (SH3) domain of PLC-1 (PLC1-SH3) bound to PIKE in glutathione S-transferase pull-down assays. Increasing concentrations of the PLC1-SH3 incubated with PIKE stimulated GTP binding to and GDP dissociation from PIKE. These data suggest that PLC1-SH3 functioned like a GEF with PIKE as its substrate. PC12 cells that expressed PLC1-SH3 exhibited increased nuclear PI3K activity, suggesting a link between PLC-1 and increased PI3K activity, and a possible explanation of how PLC-1 can promote phospholipase-independent cell proliferation.
K. Ye, B. Aghdasi, H. R. Luo, J. L. Moriarity, F. Y. Wu, J. J. Hong, K. J. Hurt, S. S. Bae, P.-G. Suh, S. H. Snyder, Phospholipase C1 is a physiological guanine nucleotide exchange factor for the nuclear GTPase PIKE. Nature 415, 541-544 (2002). [Online Journal]
Citation: PLC-1 "sPIKES" PI3K Activity. Sci. STKE 2002, tw53 (2002).
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