PIP3, PIP2, and cell movement--similar messages, different meanings?
The inositol lipids PI(4,5)P(2) and PI(3,4,5)P(3) are important regulators of actin polymerization, but their different temporal and spatial dynamics suggest that they perform separate roles. PI(3,4,5)P(3) seems to act as an instructive second messenger, inducing local actin polymerization. PI(4,5)P(2) appears to be present at too high a concentration and homogeneous a distribution to fulfil a similar role. Instead, we suggest that PI(4,5)P(2) acts permissively, restricting new actin polymerization to the region of the plasma membrane.
Insall
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RH
School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. r.h.insall@bham.ac.uk
Weiner
O D
OD
D000199:Actins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology*; D003599:Cytoskeleton / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry; D011506:Proteins / Q000378:metabolism; D015290:Second Messenger Systems / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D051316:Wiskott-Aldrich Syndrome Protein
D000199:Actins; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D011108:Polymers; D011506:Proteins; D051316:Wiskott-Aldrich Syndrome Protein; C118303:phosphoinositide-3,4,5-triphosphate