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Overexpression of MARCKS, but Not Protein Kinase C‐α, Increases Phorbol Ester‐Stimulated Synthesis of Phosphatidylcholine in Human SK‐N‐MC Neuroblastoma Cells
Author(s) -
Rosé S. D.,
Morash S. C.,
Ridgway N. D.,
Byers D. M.,
Cook H. W.
Publication year - 1996
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1996.66041766.x
Subject(s) - marcks , protein kinase c , phosphatidylcholine , microbiology and biotechnology , phorbol , phosphorylation , neuroblastoma , transfection , cell culture , biology , chemistry , biochemistry , phospholipid , genetics , membrane
To investigate the regulation of phorbol ester‐stimulated synthesis of phosphatidylcholine (PtdCho), myristoylated alanine‐rich protein kinase C substrate (MARCKS) and the α‐isoform of protein kinase C (PKC‐α) were overexpressed in a human neuroblastoma (SK‐N‐MC) cell line that does not increase PtdCho synthesis in response to 4β‐12‐ O ‐tetradecanoylphorbol 13‐acetate (TPA). In five clones with a less than fivefold increase in MARCKS protein level, the synthesis of PtdCho from [ methyl ‐ 3 H]choline was stimulated 1.88–2.34‐fold in the presence of 100–200 n M TPA. In clones overexpressing PKC‐α (30–40‐fold increased level of protein) or in mock‐transfected vector controls, TPA had much less of a stimulatory effect (1.04–1.43‐fold) on PtdCho synthesis. TPA caused translocation of PKC‐α and increased phosphorylation of MARCKS, indicating that both overexpressed proteins responded to stimulation. Thus, in SK‐N‐MC cells, MARCKS is required for TPA‐stimulated synthesis of PtdCho, and PKC‐α alone is insufficient for supporting enhanced synthesis.