Role of caveolin-1 and cytoskeletal proteins, actin and vimentin, in adipogenesis of bovine intramuscular preadipocyte cells.
We investigated the involvement of caveolin-1 and the cytoskeletal proteins, actin and vimentin, in the adipogenesis of bovine intramuscular preadipocyte (BIP) cells. Immunoblot analysis demonstrated that levels of caveolin-1 and actin gradually increased during adipose conversion in BIP cells, whereas a slight decrease was observed for vimentin. We found that part of the vimentin was clearly distributed to caveolin-1-enriched membrane fractions in BIP cells, but actin was not. During adipogenesis of BIP cells, treatment with the tubulin depolymerizer, nocodazole, significantly increased intracellular triglyceride accumulation compared to non-treated cells. Immunocytochemical analysis showed that actin microfilaments were significantly disrupted in nocodazole-treated cells. Also, a decrease in the localization of vimentin in caveolin-1-enriched fractions and a failure of vimentin to co-immunoisolate with caveolin-1 were observed in nocodazole-treated cells. These results suggest that a rearrangement of cytoskeletal proteins has a role in the intracellular accumulation of lipid droplets during adipogenesis of BIP cells.
Takenouchi
Takato
T
Laboratory of Animal Cell Biology, National Institute of Agrobiological Sciences, Kannondai 3-1-5, Tsukuba, Ibaraki 305-8602, Japan. ttakenou@affrc.go.jp
Miyashita
Norikazu
N
Ozutsumi
Kyohei
K
Rose
Michael T
MT
Aso
Hisashi
H
D000199:Actins / Q000502:physiology*; D017667:Adipocytes / Q000166:cytology* / Q000502:physiology; D000818:Animals; D002417:Cattle; D051242:Caveolin 1; D022461:Caveolins / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000502:physiology; D032342:Muscle Cells / Q000166:cytology / Q000502:physiology; D014746:Vimentin / Q000502:physiology*
D000199:Actins; D051242:Caveolin 1; D022461:Caveolins; D003598:Cytoskeletal Proteins; D014746:Vimentin