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): 1955-71, 1988 Jun.
Article
em En
| MEDLINE
| ID: mdl-3290222
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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas Quinases
/
Citoesqueleto
/
Quinase de Cadeia Leve de Miosina
/
Citoesqueleto de Actina
/
Actinas
/
Miosinas
Limite:
Animals
Idioma:
En
Ano de publicação:
1988
Tipo de documento:
Article