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Potentiation of diacylglycerol‐induced activation of protein kinase C by lysophospholipids
Author(s) -
Sasaki Yukio,
Asaoka Yoshinori,
Nishizuka Yasutomi
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81655-j
Subject(s) - diacylglycerol kinase , protein kinase c , lysophosphatidylcholine , diglyceride , phosphatidylserine , long term potentiation , microbiology and biotechnology , enzyme activator , biophysics , chemistry , biochemistry , kinase , biology , enzyme , phosphatidylcholine , phospholipid , receptor , membrane
Lysophospholipid, particularly 2‐lysophosphatidylcholine (lysoPtdCho), significantly potentiates the diacylglycerol (DAG)‐induced activation of protein kinase C (PKC) in vitro. LysoPtdCho shows no effect, unless DAG and phosphatidylserine (PtdSer) are present. This lysoPtdCho action also depends on its own as well as on Ca 2+ concentration. At physiological Ca 2+ concentrations, the activation of the α‐, β‐, and γ‐subspecies (cPKC) is enhanced by lysoPtdCho in the 10 −6 M range, but inversely inhibited in the 10 −5 M range. The δ‐ and ε‐subspecies (nPKC), which are enzymatically insensitive to Ca 2+ , are mostly inhibited by lysoPtdCho at its low concentrations. The enhancement of cPKC activation by lysoPtdCho is due to the increase in an apparent affinity of the enzyme for PtdSer but not for DAG. The results may account, at least in part, for the previous observations made with intact cell systems that lysoPtdCho significantly potentiates the DAG‐induced cellular responses such as T‐lymphocyte activation and HL‐60 cell differentiation [(1992) Trends Biochem. Sci. 17, 414–4171].