Fig. 9: The interaction between SEL1L and HRD1 is a prerequisite for a functional HRD1 ERAD complex.

a Immunoprecipitation of FLAG-agarose in SEL1L^−/− HEK293T cells transfected with indicated SEL1L-FLAG constructs to examine the interaction with HRD1, UBE2J1 and DERL2, with quantitation shown below (UBE2J1: n = 9 per group; DERL2: n = 5 per group; “n” indicates independent samples). b, c Immunoprecipitation of HRD1 in SEL1L^−/− HEK293T cells transfected with indicated SEL1L-FLAG constructs to examine the interaction between endogenous HRD1 and other ERAD components, with quantitation shown in (c) (SEL1L/OS9/ERLEC1/UBE2J1: n = 4 per group; DERL2/VCP/HERP1/FAM8A1: n = 3 per group; “n” indicates independent samples). d Immunoprecipitation of HRD1 in the livers of 5-week-old WT and KI mice to examine the endogenous HRD1 interaction with other ERAD components, with quantitation shown below the gel as means from two independent repeats. HERP1 and FAM8A1 antibodies failed to work in mouse liver tissues. e A model showing the role of SEL1L in the formation of HRD1 ERAD complex. S/P indicates S658P. Values, mean ± SEM. n.s. not significant; ***p < 0.001 and ****p < 0.0001 by two-tailed Student’s t test (a, c).