Growth factor regulation of the novel class II phosphoinositide 3-kinases.
It is well established that the class-I phosphoinositide (PI) 3-kinases play a crucial role in growth factor signalling pathways. However, evidence has recently emerged that the alpha isoform of the class-II PI 3-kinase (PI 3K-C2alpha) is activated by growth factors, although the consequences of this are poorly understood. Here we demonstrate that the activation of PI 3K-C2alpha is not associated with a change in subcellular localization. Furthermore, we provide the first evidence that PI 3K-C2beta is activated by insulin, albeit with slower kinetics than activation of PI 3K-C2alpha. These findings suggest that both these class-II PI 3-kinase isoforms are likely to participate in insulin-signalling pathways in the cell.
Brown
R A
RA
Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK.
Shepherd
P R
PR
D000818:Animals; D016466:CHO Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D004330:Drosophila; D015971:Gene Expression Regulation, Enzymologic; D006133:Growth Substances / Q000502:physiology*; D007328:Insulin / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics; D008322:Mammals; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics; D015398:Signal Transduction; D014162:Transfection
D006133:Growth Substances; D007328:Insulin; D007527:Isoenzymes; D011994:Recombinant Proteins; D019869:Phosphatidylinositol 3-Kinases