Regulation of actin microfilament integrity in living nonmuscle cells by the cAMP-dependent protein kinase and the myosin light chain kinase

Lamb, N. J., Fernandez, A., Conti, M. A., Adelstein, R., Glass, D. B., Welch, W. J., Feramisco, J. R. (June 1988) Regulation of actin microfilament integrity in living nonmuscle cells by the cAMP-dependent protein kinase and the myosin light chain kinase. J Cell Biol, 106 (6). pp. 1955-71. ISSN 0021-9525

URL: http://www.ncbi.nlm.nih.gov/pubmed/3290222
DOI: 10.1083/jcb.106.6.1955

Abstract

Microinjection of the catalytic subunit of cAMP-dependent protein kinase (A-kinase) into living fibroblasts or the treatment of these cells with agents that elevate the intracellular cAMP level caused marked alterations in cell morphology including a rounded phenotype and a complete loss of actin microfilament bundles. These effects were transient and fully reversible. Two-dimensional gel electrophoresis was used to analyze the changes in phosphoproteins from cells injected with A-kinase. These experiments showed that accompanying the disassembly of actin microfilaments, phosphorylation of myosin light chain kinase (MLCK) increased and concomitantly, the phosphorylation of myosin P-light chain decreased. Moreover, inhibiting MLCK activity via microinjection of affinity-purified antibodies specific to native MLCK caused a complete loss of microfilament bundle integrity and a decrease in myosin P-light chain phosphorylation, similar to that seen after injection of A-kinase. These data support the idea that A-kinase may regulate microfilament integrity through the phosphorylation and inhibition of MLCK activity in nonmuscle cells.

Item Type: Paper
Uncontrolled Keywords: Actins/*physiology Animals Cytoskeleton/*physiology Enzyme Activation Fluorescent Antibody Technique Immunologic Techniques In Vitro Microfilaments/*physiology Microinjections Microscopy, Electron Myosin-Light-Chain Kinase/*physiology Myosins/*physiology Phosphoproteins/physiology Protein Kinases/*physiology Rats Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. Time Factors
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > actin
Investigative techniques and equipment > assays > gel electrophoresis
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > kinase
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > myosin
CSHL Authors:
Communities: CSHL labs
Depositing User: Gail Sherman
Date: June 1988
Date Deposited: 28 Sep 2017 19:08
Last Modified: 28 Sep 2017 19:08
PMCID: PMC2115126
Related URLs:
URI: http://repository.cshl.edu/id/eprint/35172

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