Protein kinase C and T cell activation.
Understanding the intracellular mechanisms by which binding of ligands, such as hormones and growth factors, to their specific receptors elicits the appropriate cellular response has long been a topic of great interest. Considerable excitement was generated when it was recognised that several receptor-ligand interactions operate via the hydrolysis of inositol phospholipids. This yields, at least, two 'second messengers', namely, inositol 1,4,5-trisphosphate [Ins(1,4,5)P3], which causes the release of Ca2+ from intracellular stores, and 1,2-diacylglycerol (ac2Gro), which activates the serine/threonine-specific enzyme, protein kinase C(PKC), reviewed in [1] and [2]. The pertinent question that follows is, how do PKC activation and elevation of the intracellular Ca2+ concentration evoke cell responses? In this review, attention has been focused on PKC, and the consequences of its activation in resting human T cells. Evidence that PKC activity is, at least partially, responsible for activation of resting human T cells will be examined, and some of the more recent research investigating how PKC activation elicits this cell response will be described.
Berry
N
N
Department of Biochemistry, Kobe University School of Medicine, Japan.
Nishizuka
Y
Y
D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008213:Lymphocyte Activation; D008954:Models, Biological; D011493:Protein Kinase C / Q000378:metabolism*; D015290:Second Messenger Systems; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology*
D015703:Antigens, CD; D015544:Inositol 1,4,5-Trisphosphate; D011493:Protein Kinase C