Figure 8.

Solubility of synemin and its binding partners. Cardiomyocytes were transfected with synemin siRNA or a scrambled control sequence. At 4 d post-transfection, protein was extracted from cultured myocytes in MPERS buffer. Lysates were centrifuged to produce supernatant (S) and pellet (P) fractions. A) Endogenous β-synemin was predominantly found in supernatants, while α-synemin was observed in pellets. After treatment with synemin siRNA, α-synemin was no longer detected, while some β-synemin remained in the supernatant fraction in reduced amounts. B) Overexpression of α-synemin using pcDNA3-α-synemin confirmed that it concentrated in the pellet fraction, in contrast to endogenous β-synemin, which remained predominantly in supernatants. C) Desmin concentrated in the pellets, while α-actinin and vinculin were enriched in supernatants, with lesser amounts in pellets. GAPDH was found only in supernatants.