ИСТИНА

The small heat shock protein HspB6 is recognized as potential modulator of smooth muscle contraction. The molecular mechanism of relaxation induced by HspB6 remains elusive. It was earlier hypothesized that phosphorylated HspB6 displaced actin severing protein cofilin from its complex with 14-3-3 thus inducing reorganisation of actin filaments leading to smooth muscle relaxation. However method of far western blotting, native gel electroforesis, chemical crosslinking and size exclusion chromatografy failed to detect formation of tight complexes between cofilin and 14-3-3, whereas the same techniques clearly demonstrated the interaction of phosphorylated HspB6 with 14-3-3. We suggest that HspB6 can be involved in the indirect cofilin-dependent reorganization of actin cytoskeleton, displacing and activating cofilin phosphatase from its complex with 14-3-3.