Figure 4.

Association of the PDZ domain of Enigma with TM isoforms in C2C12 myotubes. (A) Detergent extracts of C2C12 myoblasts (MB) or myotubes (MT) were incubated with GST or GST-PDZ_Eng immobilized on glutathione-agarose. Two predominant forms of TM were detected in C2C12 lysates by Western blotting with anti-TM antibodies: 40- and 36-kDa forms were present in myoblasts, whereas myotubes expressed 39- and 36.5-kDa form. GST-PDZ_Eng selectively bound to the myotube-specific 39- and 36.5-kDa TM isoforms. Lysates represent 5% of the input cell extract before incubation with GST beads. (B) Anti-Enigma Western blot showing similar levels of Enigma expression in myoblasts (MB) and myotubes (MT).