Specific proteolytic cleavage of the myristoylated alanine-rich C kinase substrate between Asn 147 and Glu 148 also occurs in brain.
The myristoylated alanine-rich C kinase substrate (MARCKS) is a major ubiquitous substrate of protein kinase C. The expression of the protein is regulated during cell cycle progression and cell proliferation. Specific proteolytic cleavage of the protein between Asn 147 and Glu 148 was described recently in cultured cells, and the corresponding proteolytic activity was observed in various tissue extracts except for brain. We purified a 40 kDa fragment of MARCKS from bovine brain that we characterized as the C-terminal specific fragment found in other tissues. The identification of the fragment was achieved by in vitro phosphorylation by protein kinase C, calcium-dependent interaction with calmodulin, mass spectrometric analysis, and N-terminal sequencing. These data suggest that specific proteolytic cleavage of MARCKS also occurs in brain and may be a general mechanism of down-regulation of the protein.
Manenti
S
S
Institut National de la Santé et de la Recherche Médicale, Toulouse, France.
Taniguchi
H
H
Sorokine
O
O
Van Dorsselaer
A
A
Darbon
J M
JM
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D010446:Peptide Fragments / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D010446:Peptide Fragments; D011506:Proteins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D011493:Protein Kinase C; D010447:Peptide Hydrolases