Osteopontin stimulates gelsolin-associated phosphoinositide levels and phosphatidylinositol triphosphate-hydroxyl kinase.
Mol Biol Cell
; 7(5): 743-53, 1996 May.
Article
en En
| MEDLINE
| ID: mdl-8744948
ABSTRACT
Based on previous studies demonstrating activation of phosphatidylinositol 3-hydroxyl kinase (PI3-kinase) and stimulation of a change in cell shape, we examined the effect of osteopontin on the association of phospholipids with gelsolin, an actin-capping/severing protein. Osteopontin stimulated a rapid increase in phosphatidylinositol bisphosphate and phosphatidylinositol triphosphate levels associated with gelsolin in Triton-soluble fractions of cell lysates. The increased levels of phosphatidylinositol triphosphate associated with gelsolin were due to stimulation of PI3-kinase activity associated with gelsolin in the Triton-soluble fractions, and they were blocked by the PI3-kinase inhibitor wortmannin. Osteopontin stimulated translocation of PI3-kinase from the Triton-insoluble to Triton-soluble gelsolin. Osteopontin also decreased Triton-soluble gelsolin/actin complexes consistent with actin uncapping, and increased F-actin levels, which were also blocked by wortmannin. The osteopontin effects were mediated through binding to the alpha(v)beta 3 integrin. Taken together, our studies indicate that osteopontin/alpha(v)beta 3-mediated changes in gelsolin-associated phosphoinositide levels and PI3-kinase activity are related to stimulation of F-actin formation in osteoclasts.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Osteoclastos
/
Sialoglicoproteínas
/
Fosfotransferasas (Aceptor de Grupo Alcohol)
/
Gelsolina
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
Mol Biol Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
1996
Tipo del documento:
Article
País de afiliación:
Estados Unidos