TRIM21 is involved in SALL4 degradation.
A, immunoblot image of SALL4 protein is shown. MCF-7 and SUM159 cells were treated with MG-132 (n = 3). The arrow indicates SALL4B bands. B, SALL4B-EGFP probe is depicted. C, relative mRNA levels of TRIM21 are shown. shRNA-mediated TRIM21 knockdown was performed in MCF-7 cells. D, immunoblot image of SALL4B-EGFP probe is shown (n = 4 TRIM21 knockdown constructs). The arrow indicates the position of SALL4B-EGFP. shScr was used as a control. E, immunoblot for EGFP is shown (n = 3). shTRIM21-5 was used. F, relative mRNA levels of TRIM21 and SALL4 are shown. TRIM21 knockdown with shTRIM21-5 was performed in SUM159 cells. n.s., not significant; **, p < 0.01 compared with shScr control (Student's t test). Error bars indicate standard deviations (n = 3).