Fig. 7: TRIM21 increases prolyl 4-hydroxylase subunit alpha-2 (P4HA2) ubiquitination through the RING domain to reduce the protein stability of P4HA2.

A Protein from BCPAP cells, anti-P4HA2 and IgG antibodies were used for immunoprecipitation (IP), and the IP products were identified by MS. The interaction between P4HA2 and TRIM21 was verified through Co-IP (B) and immunofluorescence techniques (C). D After transfection in 293 T cells with the corresponding plasmid, the effect of TRIM21 overexpression on P4HA2 protein was detected by Western blotting assay. E The interaction between P4HA2 and ΔTRIM21 was detected by Co-IP after transfection of the corresponding plasmid. The effects of TRIM21 (F), siTRIM21 (G), and ΔTRIM21 (H) on P4HA2 ubiquitination were detected by Co-IP after transfection with the corresponding plasmid. I, J BCPAP and 293 T cells were transfected with corresponding plasmids for 48 h, then treated with MG132 or DMSO for 8 h, and the proteins were extracted for Western blotting. K–N BCPAP and 293 T cells were transfected with the corresponding plasmids for 48 h, and then CHX or DMSO intervention was performed for 0, 2, 4, and 8 h, and the proteins were extracted for Western blotting. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.