Figure 9.

Interactions of synemin with α-actinin and vinculin. A) α-Actinin (110 kDa) was immunoprecipitated from lysates of neonatal cardiomyocytes after 4 d in culture. α-Actinin (arrow) coimmunoprecipitated with synemin when cell lysates were incubated with the Syn-MAb but not with an anti-His antibody (negative control; n=3). B) Both α- and β-synemin (arrows) immunoprecipitated with the Syn-MAb (180 and 210 kDa). Immunoprecipitating with an anti-sarcomeric α-actinin antibody coimmunoprecipitated β-synemin. C) Vinculin (middle arrow) and metavinculin (top arrow), 110 and 150 kDa respectively, immunoprecipitated with the vinculin antibody. However, the Syn-MAb coimmunoprecipitated only vinculin and not metavinculin, along with a second unidentified band (estimated 100 kDa; bottom arrow). D) Immunoprecipitates prepared with antibodies to sarcomeric α-actinin and vinculin showed that β-synemin preferentially coimmunoprecipitated with α-actinin. Detectable amounts of α- and β-synemin were present in vinculin immunoprecipitates.