title: Rapid stimulatory effect of insulin on binding of glycolytic enzymes to cytoskeleton of C-6 glial cells, and the antagonistic action of calmodulin inhibitors.
abstract: Insulin was shown in our previous experiments to induce an increase in binding of glycolytic enzymes to muscle cytoskeleton. We show here the same stimulatory effect of insulin in C-6 glial cells in culture. In these cells, like in muscle, a short time of incubation with insulin (1-10 min) induced an increase in cytoskeleton bound phosphofructokinase and aldolase. This stimulatory effect of insulin could be prevented by treatment with calmodulin antagonists trifluoperazine, thioridazine or CGS 9343 B (a potent and selective inhibitor of calmodulin activity), which strongly suggests that calmodulin is involved in this action of insulin. Our previous experiments have shown that growth factors and Ca(2+) also induce a rapid, calmodulin-mediated stimulation of binding of glycolytic enzymes to cytoskeleton. The present and previous results suggest that the rapid binding of glycolytic enzymes to cytoskeleton, may be a general mechanism, in different cells, in signal transduction of insulin, growth factors and other Ca(2+) -mobilizing hormones. The accelerated cytoskeletal glycolysis will supply local ATP, which is required for the rapid cytoskeletal-membrane rearrangements following the binding of hormone to its receptor.
authors.affiliation: Dept. of Life Sciences, Bar-llan University Ramat Can, 52900, Israel.
authors.forename: T
authors.initials: T
authors.lastname: Livnat
authors.forename: M
authors.initials: M
authors.lastname: Chen-Zion
authors.forename: C
authors.initials: C
authors.lastname: Brodie
authors.forename: R
authors.initials: R
authors.lastname: Beitner