Fig. 4.

HSPB7 binds G actin and inhibits actin polymerization. (A) Silver stain image of F-actin cosedimentation binding assay. S, supernatant; P, pellet. (B) TAP performed in isolated neonatal mouse cardiomyocytes infected by adenoviruses expressing either 3xFLAG/HA-tagged HSPB7 or EGFP. Samples were immunoblotted with actin or FLAG antibodies. The residual amount of actin in control EGFP sample is caused by unspecific binding of actin to EGFP, which was expressed at a much higher level than HSPB7. (C) Western blot image of blot overlay assay using an antibody against HSPB7 (Upper). Fluorescence image of Alexa Flour 594-conjugated DNase I incubated with the same membrane after treatment with stripping buffer (Lower). IB, immunoblot. (D) Actin polymerization assay with or without the presence of recombinant HSPB7 protein. Pyrene labeled G actin (2 μM) was preincubated with increasing amount of HSPB7 (10 μM, green; 40 μM, magenta) or buffer alone (blue).