Occurrence and functions of the phosphatidylinositol cycle in the myocardium.
In the last decade a great deal of attention was awarded to a signal transduction pathway which is utilized primarily by 'Ca2+ mobilizing' signal molecules and which involves the hydrolysis of a quantitatively minor phospholipid, phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) by a PtdIns-specific phospholipase C (PLC). The evidence for the existence of receptor-mediated GTP binding protein-coupled PLC in myocardium and its possible functions are briefly summarized. The minireview is concentrated on the following aspects: 1) cellular localization and synthesis of polyphospho-PtdIns from PtdIns, 2) desensitization of the alpha 1-adrenergic agonist and endothelin-1 mediated PtdIns responses, 3) oscillatory Ca2+ transients initiated by PtdIns(4,5)P2 hydrolysis, 4) polyunsaturated fatty acids as constituents of polyphospho-PtdIns and of the protein kinase C activator 1,2-diacylglycerol (DAG), 5) source other than PtdIns(4,5)P2 contributing to the stimulated DAG, 6) role of the PtdIns pathway in cardiomyocyte growth and gene expression during the hypertrophic response.
Lamers
J M
JM
Department of Biochemistry, Faculty of Medicine and Health Sciences, Erasmus University Rotterdam, The Netherlands.
Dekkers
D H
DH
Bezstarosti
K
K
Meij
J T
JT
van Heugten
H A
HA
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002455:Cell Division; D004075:Diglycerides / Q000378:metabolism; D016232:Endothelins / Q000494:pharmacology; D004789:Enzyme Activation; D005227:Fatty Acids / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D008563:Membrane Lipids / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D015398:Signal Transduction
C011439:1,2-diacylglycerol; D000316:Adrenergic alpha-Agonists; D004075:Diglycerides; D016232:Endothelins; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008563:Membrane Lipids; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D011493:Protein Kinase C; D002118:Calcium