Open Access
Identification of myristoylated alanine-rich C kinase substrate (MARCKS) in astrocytes
Ljubisa Vitkovic1,Vincent J Aloyo1,Shigeru Maeda1,Deborha L Benzil1,Joseph P Bressler1,Dana C Hilt1
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA. <>
DOI: 10.2741/1517 Volume 10 Issue 1, pp.160-165
Published: 01 January 2005
(This article belongs to the Special Issue Inflammatory disorders of the nervous system)

We have characterized membrane-associated substrates of Ca2+-dependent kinases in primary rat astrocytes by in vitro phosphorylation, 2-dimensional gel electrophoresis and autoradiography. The most prominent among these were three acidic, protein kinase C (PKC) substrates. These are important because they likely transduce cytokine and other neuro-immune modulatory signals mediated by PKC. We now show that one of these phosphoproteins is myristoylated alanine-rich PKC kinase substrate (MARCKS) or phosphomyristin C. The identity was corroborated by one- and 2- dimensional immunoblotting with an MARCKS-specific polyclonal antibody. Exposing primary astrocytes to phorbol 12-myristate 13-acetate stimulated phosphorylation of this protein. The level of MARCKS appeared inversely proportional to the proliferative potential of astrocytes because it was lower in spontaneously transformed as compared to passaged or confluent cells. These data are consistent with previous reports and indicate that one of three major acidic membrane-associated PKC substrates in astrocytes is MARCKS. Thus, MARCKS is likely near-proximal transducer of PKC-mediated signals in astrocytes.

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Ljubisa Vitkovic, Vincent J Aloyo, Shigeru Maeda, Deborha L Benzil, Joseph P Bressler, Dana C Hilt. Identification of myristoylated alanine-rich C kinase substrate (MARCKS) in astrocytes. Frontiers in Bioscience-Landmark. 2005. 10(1); 160-165.