Fig 2.

Association between cav-1 and TGFβ-RI/Alk1 in dermal fibroblasts. (A) Primary cultures of human dermal fibroblasts were grown to subconfluence and serum starved for 24 hrs. Protein from whole cell lysate was subjected to immunoprecipitation using mouse anti-Alk1 antibody (Alk1), and cav-1 was detected by immunoblotting using rabbit anti-caveolin-1 antibody (caveolin 1). The specific cav-1 protein appears in a band at 22 kD. (B) Alk1 was up-regulated in human dermal fibroblasts using adenovirus mediated overexpression, and cells were serum starved for 24 hrs and treated with TGFβ for 15 min prior to collection of whole cell lysates. Immunoprecipitation was again performed using mouse anti-Alk1 antibody, and caveolin-1 levels were detected by western blot of the Alk1 bound fraction (top panel), and input whole cell lysate (bottom panels). Western blot of whole cell lysate was stripped and reprobed for β-actin as a loading control.