Mutual protection of microtubule-associated protein 2 (MAP2) and cyclic AMP-dependent protein kinase II against mu-calpain.

TitleMutual protection of microtubule-associated protein 2 (MAP2) and cyclic AMP-dependent protein kinase II against mu-calpain.
Publication TypeJournal Article
Year of Publication1996
AuthorsAlexa, A., P. Tompa, A. Baki, G. Vereb, and P. Friedrich
JournalJ Neurosci Res
Volume44
Issue5
Pagination438-45
Date Published1996 Jun 1
ISSN0360-4012
KeywordsAnimals, Calpain, Cyclic AMP, Enzyme Activation, Microtubule-Associated Proteins, Phosphorylation, Protein Kinases, Rats, Rats, Wistar, Time Factors
Abstract

Phosphorylation by adenosine-3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (PKA), but not by Ca(++)-calmodulin-dependent protein kinase II (CaMK II), was shown earlier to protect microtubule-associated protein 2 (MAP2) from cleavage by m-calpain (Johnson and Foley: J Neurosci Res 34: 642-647, 1993). We reinvestigated this phenomenon with the physiologically more relevant mu-calpain and found a qualitatively similar but quantitatively different picture. We further demonstrate that 1) protection is biphasically dependent on the degree of phosphorylation; 2) Ca(++)-phospholipid-dependent protein kinase (PKC) has about the same effect as PKA; 3) the effects of kinases A and C are not additive; and 4) stripping of native MAP2 from its phosphate content (17.8 +/- 2.3 mol/mol) enhances calpainolysis 3.6-fold. A reciprocal effect between kinase A and MAP2 was found: the RII, but not the RI, regulatory subunit of kinase A, which was shown to bind specifically to MAP2, is protected by MAP2 from mu-calpain attack. It is suggested that the specific anchoring of kinase A-II on MAP2 may serve not only kinase targeting in the dendrites, but also protection from calpainolytic degradation.

DOI10.1002/(SICI)1097-4547(19960601)44:5<438::AID-JNR4>3.0.CO;2-G
Alternate JournalJ. Neurosci. Res.
PubMed ID8776665