Induction of HRD1 and SEL1L expression by ER stress-inducing agents.

<p><i>A</i>. Real-time PCR analysis of gene expression in N2a cells treated for 24 h with or without tunicamycin (Tm; an inhibitor of <i>N</i>-linked glycosylation) and thapsigargin (Tg; an inhibitor of Ca²⁺ ATPase). Data are normalized to the amount of β-actin; results are expressed as a fold increase compared with the non-treated control (mean ± SEM; <i>n</i> = 3). Statistical analysis was performed with ANOVA, followed by Bonferroni correction (Control vs. Tm and Tg; *<i>p</i><0.05). <i>B-C.</i> Western blotting of (<i>B</i>) NP-40-soluble and (<i>C</i>) -insoluble fractions from N2a cells treated with or without Tm and Tg for 24 h using the indicated antibodies. The black arrow in soluble fraction indicates mature SEL1L, and the white arrow indicates immature SEL1L without glycosylation.