Effect of mevalonate availability on the association of G-protein alpha-subunits with the plasma membrane in GH4C1 cells.
FEBS Lett
; 401(1): 68-72, 1997 Jan 13.
Article
en En
| MEDLINE
| ID: mdl-9003808
We show that the levels and activity of the alpha-subunits of Gs and Gi proteins in plasma membrane of GH4C1 cells are regulated by the availability of mevalonate (MVA), and not by changes in cholesterol cell content. Changes in the levels of MVA, induced by modulation of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, determine the amount of both membrane-bound G alpha-subunits, which correlated with the activity of their effector adenylyl cyclase. Lipoprotein deficient serum (LPDS) decreases cholesterol content and increases both HMG-CoA reductase activity and G alpha-subunits in the membrane. Cholesterol and 25-hydroxycholesterol (25-HC) each repress HMG-CoA reductase and diminish G alpha-subunit levels. However, while cholesterol cell content is also decreased by 25-HC, exogenous cholesterol increases it. In addition, the decrease of both G alpha-subunits is reversed by the presence of MVA. This regulation appears to be mediated by nonsterol products generated from MVA. We assume that the first is the prenylation of the gamma-subunits, since the attachment of G alpha-subunits to the membrane is dependent on this modification. However, as neither of our treatments completely abolished protein prenylation, we conclude that another MVA derivative is required in addition to prenyl residues to the presence and activity of alpha-subunits in the membrane.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Unión al GTP
/
Ácido Mevalónico
Tipo de estudio:
Risk_factors_studies
Idioma:
En
Revista:
FEBS Lett
Año:
1997
Tipo del documento:
Article
País de afiliación:
España
Pais de publicación:
Reino Unido