Fig. 4: DNAJA4 promotes the degradation of MYH9 by enhancing its ubiquitination.

A SDS-PAGE and silver staining of proteins isolated from SUNE1 cells transfected with HA-DNAJA4 plasmid and subjected to co-immunoprecipitation with an anti-HA-tag antibody. B Co-IP followed by western blotting using anti-HA or anti-Flag antibodies revealed the exogenous association of DNAJA4 and MYH9 in HONE1 and SUNE1 cells. C Immunofluorescence staining indicated the cellular localization of endogenous MYH9 and DNAJA4 in HONE1 and SUNE1 cells. Scale bar, 50 μm. D The mRNA levels of MYH9 in HONE1 and SUNE1 cells transfected with the DNAJA4 overexpression or empty plasmid. E The protein levels of MYH9 in HONE1 and SUNE1 cells transfected with the DNAJA4 overexpression or empty plasmid. F The mRNA levels of MYH9 in HONE1 and SUNE1 cells transfected with the shNC or shDNAJA4 plasmid. G The protein levels of MYH9 in HONE1 and SUNE1 cells transfected with the shNC or shDNAJA4 plasmid. H The effect of CHX treatment and greyscale analysis of MYH9 protein levels in HONE1 cells transfected with the DNAJA4 overexpression or empty plasmid. I MG132 and CQ treatment in HONE1 cells transfected with the DNAJA4 overexpression or empty plasmid. J HONE1 and SUNE1 cells transfected with the indicated plasmids were subjected to denaturing-IP, and the ubiquitination of MYH9 and the indicated proteins was exogenously detected. The data in (D, F, H) are shown as the mean ± SD, and p-values were determined by Student’s t test (ns, not significant; *p < 0.05).