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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2011-4-13
pubmed:abstractText
Cyclin-dependent kinase 5 (Cdk5) is a Ser/Thr kinase that is activated by binding to its regulatory subunit, p35. The calpain-mediated cleavage of p35 to p25 and the resulting aberrant activity and neurotoxicity of Cdk5 have been implicated in neurological disorders, such as Alzheimer's disease. To gain further insight into the molecular mechanisms underlying the pathological function of Cdk5, we investigated the role of the calpain inhibitor protein calpastatin (CAST), in controlling the aberrant production of p25. For this purpose, brain tissue from wild-type, CAST-over-expressing (transgenic), and CAST knockout mice were analyzed. Cleavage of p35 to p25 was increased in extracts from CAST knockout mice, compared with wild-type. Conversely, generation of p25 was not detected in brain lysates from CAST-over-expressing mice. CAST expression was 5-fold higher in mouse cerebellum than cerebral cortex. Accordingly, p25 production was lower in the cerebellum than the cerebral cortex. Furthermore, the Ca(2+) -dependent degradation of p35 by proteasome was evident when calpain was inhibited. Taken together, these results suggest that CAST is a crucial regulator of calpain activity, the production of p25, and, hence, the deregulation of Cdk5. Therefore, impairment of CAST expression and its associated mechanisms may contribute to the pathogenesis of neurodegenerative disorders.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1471-4159
pubmed:author
pubmed:copyrightInfo
© 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.
pubmed:issnType
Electronic
pubmed:volume
117
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
504-15
pubmed:meshHeading
pubmed-meshheading:21338355-Alzheimer Disease, pubmed-meshheading:21338355-Animals, pubmed-meshheading:21338355-Brain, pubmed-meshheading:21338355-Calcium, pubmed-meshheading:21338355-Calcium-Binding Proteins, pubmed-meshheading:21338355-Cells, Cultured, pubmed-meshheading:21338355-Cyclin-Dependent Kinase 5, pubmed-meshheading:21338355-Disease Models, Animal, pubmed-meshheading:21338355-Enzyme Inhibitors, pubmed-meshheading:21338355-Gene Expression Regulation, Enzymologic, pubmed-meshheading:21338355-Humans, pubmed-meshheading:21338355-Mice, pubmed-meshheading:21338355-Mice, Inbred ICR, pubmed-meshheading:21338355-Mice, Transgenic, pubmed-meshheading:21338355-Nerve Tissue Proteins, pubmed-meshheading:21338355-Neurons, pubmed-meshheading:21338355-Proteasome Endopeptidase Complex, pubmed-meshheading:21338355-Reperfusion Injury
pubmed:year
2011
pubmed:articleTitle
Calpastatin, an endogenous calpain-inhibitor protein, regulates the cleavage of the Cdk5 activator p35 to p25.
pubmed:affiliation
Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't