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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-6-5
pubmed:abstractText
We have identified a highly active Ca2+ calmodulin-dependent protein kinase in the cytoskeletons of normal (bovine fasciculata) and transformed (Y-1 mouse tumor) adrenal cells. In view of evidence for the involvement of calmodulin and microfilaments in the regulation of cholesterol transport and hence steroidogenesis, it is likely that this kinase is important in this process. The kinase activity was examined for its capacity to phosphorylate endogenous proteins analyzed by one- and two-dimensional gel electrophoresis, in the presence of saturating amounts of Ca2+ (5 mM) and calmodulin (5 microM). Three inhibitors of calmodulin (trifluoperazine, pimozide and W-7) inhibit steroidogenesis and Ca2(+)-calmodulin-dependent phosphorylation kinase activity with similar values for EC50 for the two processes. All three inhibitors inhibit the increased transport of cholesterol to mitochondria in response to ACTH. Two substrates for the kinase (alpha-spectrin and beta-tubulin) were identified and two others (51,000 and 60,000 molecular weight) were tentatively identified as the subunits of the kinase itself in cytoskeletons of both cell types. Calmodulin-binding proteins analyzed by [125I]iodocalmodulin overlay and calmodulin-Sepharose affinity chromatography were also identified in the same cytoskeletons including alpha-spectrin, the Ca2+ calmodulin-dependent phosphatase calcineurin and three that were tentatively identified as the two subunits of the kinase itself and myosin light chain kinase. It is concluded that calmodulin, by binding to the kinase and phosphatase, is capable of influencing the degree of phosphorylation of specific substrates in the cytoskeleton and of forming complexes with spectrin, actin and tubulin. These events may be involved in the regulation of the rate-limiting step of steroidogenesis, i.e. transport of cholesterol to mitochondria.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0303-7207
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
74
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
109-23
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:1965307-Adrenal Gland Neoplasms, pubmed-meshheading:1965307-Adrenocorticotropic Hormone, pubmed-meshheading:1965307-Animals, pubmed-meshheading:1965307-Calcium, pubmed-meshheading:1965307-Calcium-Calmodulin-Dependent Protein Kinases, pubmed-meshheading:1965307-Calmodulin, pubmed-meshheading:1965307-Calmodulin-Binding Proteins, pubmed-meshheading:1965307-Cattle, pubmed-meshheading:1965307-Cell Transformation, Neoplastic, pubmed-meshheading:1965307-Cytoskeleton, pubmed-meshheading:1965307-Electrophoresis, Gel, Two-Dimensional, pubmed-meshheading:1965307-Kinetics, pubmed-meshheading:1965307-Mice, pubmed-meshheading:1965307-Phosphoric Diester Hydrolases, pubmed-meshheading:1965307-Phosphorylation, pubmed-meshheading:1965307-Protein Kinases, pubmed-meshheading:1965307-Substrate Specificity, pubmed-meshheading:1965307-Tumor Cells, Cultured, pubmed-meshheading:1965307-Zona Fasciculata
pubmed:year
1990
pubmed:articleTitle
Calcium-calmodulin-dependent phosphorylation of cytoskeletal proteins from adrenal cells.
pubmed:affiliation
Department of Endocrinology, Prince of Wales Hospital, Randwick, N.S.W., Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't