| 17379189 |
Weisinger G, Limor R, Marcus-Perlman Y, Knoll E, Kohen F, Schinder V, Firer M, Stern N: 12S-lipoxygenase protein associates with alpha-actin fibers in human umbilical artery vascular smooth muscle cells. Biochem Biophys Res Commun. 2007 May 11;356(3):554-60. Epub 2007 Mar 12.
The current study sets out to characterize the intracellular localization of the platelet-type 12S-lipoxygenase (12-LO), an enzyme involved in angiotensin-II induced signaling in vascular smooth muscle cells (VSMC). Immunohistochemical analysis of VSMC in vitro or human umbilical arteries in vivo showed a clear cytoplasmic localization. On immunogold electron microscopy, 12-LO was found primarily associated with cytoplasmic VSMC muscle fibrils. Upon angiotensin-II treatment of cultured VSMC, immunoprecipitated 12-LO was found bound to alpha-actin, a component of the cytoplasmic myofilaments. 12-LO/alpha-actin binding was blocked by VSMC pretreatment with the 12-LO inhibitors, baicalien or esculetine and the protein synthesis inhibitor, cycloheximide. Moreover, the binding of 12-LO to alpha-actin was not associated with 12-LO serine or tyrosine phosphorylation. These observations suggest a previously unrecognized angiotensin-II dependent protein interaction in VSMC through which 12-LO protein may be trafficked, for yet undiscovered purposes towards the much more abundantly expressed cytoskeletal protein alpha-actin. |
34(0,1,1,4) |