Fig. 1: ELK3 stability was regulated by Cul3-mediated proteasome pathway.

a–c Determination of ELK3 degradation pathways. The cell lysates extracted from HeLa cells treated with MG132 (a), chloroquine (b), or MLN4924 (c) were used to visualize ELK3 by WB. d ELK3 interaction with Cullin3. The cell lysates extracted from HEK293T cells transfected with indicated plasmids and treated with MG132 (10 μM) for 4 h were used to evaluate the interaction between ELK3 and each of Cullins by IP and WB. e Cullin3 decreases ELK3 half-life. The cell lysates extracted from HEK293T cells transfected with indicated plasmids and treated with cycloheximide (CHX, 10 μg/ml) were used to evaluate the half-life of ELK3 by WB. f Knockdown of Cullin3 increases ELK3. The cell lysates extracted from HeLa cells stably expressing sh-mock or sh-CUL3 were used to evaluate the ELK3 protein levels by WB. g Cullin3 knockdown inhibits ELK3 destabilization. The cell lysates extracted from PC-3 cells stably expressing sh-mock or sh-Cul3 and treated with CHX (10 μg/ml) were used to evaluate the ELK3 half-life by WB. h Cullin3 induces ELK3 ubiquitination. The cell lysates extracted from HEK293T cells transfected with indicated plasmids and treated with MG132 (10 μM) for 4 h were used to evaluate the ELK3 ubiquitination by IP and WB. Graphs in e and g The band intensity ELK3 bands measured using NIH image J computer program and normalized by β-actin intensity were plotted. Data, three independent experiments; Significance, *p < 0.05 obtained by Student t test.