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Abnormal behavior of protein kinase C in the human myeloma cell line, RPMI 8226
Author(s) -
Parant Marc R.,
Klein Bernard,
Vial Henri
Publication year - 1990
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(90)81187-s
Subject(s) - cytosol , proteolysis , protein kinase c , membrane , chemistry , cell culture , biochemistry , protein kinase a , endogeny , cell membrane , kinase , biology , enzyme , genetics
Protein kinase C activity of the human myeloma cell line, RPMI 8226, was studied after prepurification on DEAE‐cellulose. The total protein kinase activity, eluted at 0.12 M NaCl, was 493 cells, but 38% was associated with membranes. The lipid dependence of cytosolic and membrane activities was only 52% and 21%, respectively. This activity increased with time, to as much as 200% for the membrane fraction after 7 days, whereas lipid dependence and the PDBu binding properties were lost. This modified activity was not due to the extinction of a copurifying endogenous inhibitor nor to classical PKC proteolysis. TPA‐treatment of these eels is accompanied by a rapid, selective and complete loss of lipid‐dependent activity of the cytosol, thus benefiting co‐migrating lipid independent activity, with no membrane fraction recovery or PKM formation.