PIPkins1, their substrates and their products: new functions for old enzymes.
The phosphatidylinositolphosphate kinases (PIPkins) are a unique family of enzymes that catalyse the production of phosphorylated inositol lipids. Recent advances have revealed that, due to their ability to utilise a number of different lipid substrates (at least in vitro), this family is potentially able to generate several distinct, physiologically important inositol lipids. Despite their importance, however, our understanding of the regulation of the PIPkins and of their physiological role in cellular signalling and regulation is still poor. Here we describe in turn the diverse physiological functions of the known substrates and major products of the PIPkins. We then examine what is known about the members of the PIPkin family themselves, and their characteristics and regulation.
Hinchliffe
K A
KA
University of Cambridge, Department of Pharmacology, Tennis Court Road, Cambridge CB2 1QJ, UK. kh224@cam.ac.uk
Ciruela
A
A
Irvine
R F
RF
D000818:Animals; D006801:Humans; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D015398:Signal Transduction; D013379:Substrate Specificity
D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; C060980:phosphatidylinositol 3,4-diphosphate; C106336:phosphatidylinositol 3,5-diphosphate; C055525:phosphatidylinositol 3-phosphate; C037178:phosphatidylinositol 4-phosphate; C113567:phosphatidylinositol 5-phosphate; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase