[Role of protein kinase C in cell regulation and tumor promotion].
The signaling pathways which transfer information into the cell form a tissue-specific network. Protein kinase C (PKC) belongs to the inositol 1, 4, 5 trisphosphate/diacylglycerol (IP3/DG) pathway and plays a key role in cell regulation. The enzyme controls cell growth and functions through a set of negative and positive regulatory mechanisms. Some tumor promoters such as phorbol esters activate PKC by acting at the DG binding site. Others do not compete with DG and either activate PKC in the absence of phospholipids, such as arachidonic acid and bile salts, or require the presence of phospholipids, for instance a number of organic solvents. However, some promoters do not directly activate the enzyme although some of them appear to act elsewhere in the IP3/DG signaling pathway. The possibility that tumor promoters impair the expression of PKC is discussed.
IRSC Villejuif, France.
M
M
Castagna
I
I
Martelly
D002273:Carcinogens; D002455:Cell Division; D002468:Cell Physiological Phenomena; D004789:Enzyme Activation; D006131:Growth Inhibitors / Q000502:physiology; D006801:Humans; D009857:Oncogenes; D011493:Protein Kinase C / Q000378:metabolism* / Q000502:physiology
D002273:Carcinogens; D006131:Growth Inhibitors; D011493:Protein Kinase C
Rôle de la protéine kinase C dans les régulations cellulaires et la promotion tumorale.