Ca2+– and Calmodulin‐Dependent Phosphorylation of Microtubule‐Associated Protein 2 and t Factor, and Inhibition of Microtubule Assembly
- 1 April 1983
- journal article
- Published by Wiley in Journal of Neurochemistry
- Vol. 41 (4), 1119-1125
- https://doi.org/10.1111/j.1471-4159.1983.tb09060.x
Abstract
Microtubule-associated proteins (MAPs) were phosphorylated by a Ca2+- and calmodulin-dependent protein kinase from rat brain cytosol. The maximal amount of phosphate incorporated into MAPs was 25 nmol of phosphate/mg protein. A Ka value of the enzyme for calmodulin was 57.0 nM, with MAPs as substrates. Among MAPs, MAP2 and tau factor were phosphorylated in a Ca2+- and calmodulin-dependent manner. The phosphorylation of MAPs led to an inhibition of microtubule assembly in accordance with its degree. This reaction was dependent on addition of the enzyme, Ca2+, and calmodulin, and had a greater effect on the initial rate of microtubule assembly rather than on the final extent. The critical tubulin concentration for microtubule assembly was unchanged by the MAPs phosphorylation. Therefore assembly and disassembly of brain microtubule are regulated by the Ca2+- and calmodulin-dependent protein kinase that requires only a nanomolar concentration of calmodulin for activation.Keywords
This publication has 36 references indexed in Scilit:
- Phosphorylation of microtubule-associated protein 2 by calmodulin-dependent protein kinase (Kinase II) which occurs only in the brain tissuesBiochemical and Biophysical Research Communications, 1982
- Multiple specificities of brain Ca2+- and calmodulin-dependent protein kinase for substrateLife Sciences, 1982
- Occurrence of Two Types of Ca2+‐Dependent Protein Kinases in the Cytosol Fraction of the BrainJournal of Neurochemistry, 1981
- Ca2+‐ and calmodulin‐dependent flip—flop mechanism in microtubule assembly—disassemblyFEBS Letters, 1981
- The calmodulin‐binding protein in microtubules is tau factorFEBS Letters, 1981
- Calmodulin—an intracellular calcium receptorNature, 1980
- The L‐2 light chain of chicken skeletal muscle myosinFEBS Letters, 1977
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976
- Turbidimetric studies of the in vitro assembly and disassembly of porcine neurotubulesJournal of Molecular Biology, 1974
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970