Differential expression of MARCKS and other calmodulin-binding protein kinase C substrates in cultured neuroblastoma and glioma cells.

Abstract

Expression of the protein kinase C substrate MARCKS and other heat-stable myristoylated proteins have been studied in four cultured neural cell lines. Amounts of MARCKS protein, measured by [3H]myristate labeling and western blotting, were severalfold higher in rat C6 glioma and human HTB-11 (SK-N-SH) neuroblastoma cells than in HTB-10 (SK-N-MC) or mouse N1E-115 neuroblastoma cells. Higher levels of MARCKS mRNA were also detected in the former cell lines by S1 nuclease protection assay. At least two additional 3H-myristoylated proteins of 50 and 40-45 kDa were observed in cell extracts heated to > 80 degrees C or treated with perchloric acid. The 50-kDa protein, which bound to calmodulin in the presence of Ca2+, was more prominent in cells (N1E-115 and HTB-10) with less MARCKS, whereas neuromodulin (GAP-43) was detected in N1E-115 and HTB-11 cells only. Heating resulted in a fourfold increase in the detection of MARCKS by western blotting; this was not paralleled by a similar increase in [3H]myristate-labeled MARCKS and may be due to a conformational change affecting the C-terminal epitope or enhanced rechange of the protein on nitrocellulose. Addition of beta-12-O-tetradecanoylphorbol 13-acetate resulted in three- to fourfold increased phosphorylation of MARCKS in HTB-11 cells, with little increase noted in HTB-10 cells. These results indicate that MARCKS, neuromodulin, and other calmodulin-binding protein kinase C substrates exhibit distinct levels of expression in cultured neurotumor cell lines. Of these proteins, only MARCKS appears to be correlated with phorbol ester stimulation of phosphatidylcholine turnover in these cells.

• Authors: S D Rosé, H W Cook, F B Palmer, N D Ridgway, D M Byers
• Journal: Journal of neurochemistry (J Neurochem) Vol. 63 Issue 6 Pg. 2314-23 (Dec 1994) ISSN: 0022-3042 [Print] England
• PMID: 7964753 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Calmodulin
• GAP-43 Protein
• Intracellular Signaling Peptides and Proteins
• MARCKS protein, human
• Marcks protein, mouse
• Marcks protein, rat
• Membrane Glycoproteins
• Membrane Proteins
• Myristic Acids
• Nerve Tissue Proteins
• Proteins
• RNA, Messenger
• Myristic Acid
• Myristoylated Alanine-Rich C Kinase Substrate
• Protein Kinase C
• Tetradecanoylphorbol Acetate

Topics

• Amino Acid Sequence
• Animals
• Calmodulin (metabolism)
• GAP-43 Protein
• Gene Expression
• Glioma (metabolism)
• Hot Temperature
• Humans
• Intracellular Signaling Peptides and Proteins
• Membrane Glycoproteins (metabolism)
• Membrane Proteins
• Mice
• Molecular Sequence Data
• Myristic Acid
• Myristic Acids (metabolism)
• Myristoylated Alanine-Rich C Kinase Substrate
• Nerve Tissue Proteins (metabolism)
• Neuroblastoma (metabolism)
• Phosphorylation
• Protein Kinase C (metabolism)
• Proteins (chemistry, genetics, metabolism)
• RNA, Messenger (metabolism)
• Rats
• Tetradecanoylphorbol Acetate (pharmacology)
• Tumor Cells, Cultured