Fig 2: MiR-101 expression is inversely correlated with the mRNA expression of suppressor enhancer Lin12 1-like (SEL1L). (A) Potential targets of SEL1L predicted by the interrogation of four databases (Targetscan, PicTar, miRanda, and miRDB). (B) SH-SY5Y cells were stimulated with 25, 50, or 70 µM 6-hydroxydopamine (6-OHDA) for 12 h. Data on cell viability are expressed as means ± standard error of the mean of three (TBE assay) or four (MTT assay) independent experiments performed in duplicate. *p < 0.05, **p < 0.01, and ***p < 0.001, one-way analysis of variance with Dunnett’s post hoc test. (C,D) SH-SY5Y cells were stimulated with 25 µM 6-OHDA for 12, 24, or 48 h. The relative expression levels of SEL1L mRNA, miR-101, and miR-181a-2 are presented as means ± standard error of the mean of at least four independent experiments performed in duplicate. *p < 0.05 and **p < 0.01, one-way analysis of variance with Tukey’s post hoc test.

Fig 3: MiR-101 regulates the suppressor enhancer Lin12 1-like (SEL1L) 3'-untranslated region (3'-UTR). (A) Schematic diagram of the miR-101 target site in the 3'-UTR of SEL1L mRNA. (B) Luciferase reporter assay was performed in SH-SY5Y cells cotransfected with vectors carrying the wild-type (pmirGLO-SEL1L-3'-UTR-WT) or mutant (pmirGLO-SEL1L-3'-UTR-MUT) SEL1L 3'-UTR construct together with the miR-101 mimic or negative control (NC) for 24 h. Data are presented as means ± standard error of the mean of the relative ratio of firefly luciferase activity to Renilla luciferase activity in three independent experiments performed in triplicate. *p < 0.05, Student’s t test.

Fig 4: Sigmar1 mediates SERCA2 degradation through the Hrd1/Sel1L-dependent ERAD pathway A, BWestern blots showing SERCA2 expression in HEK-293T cells with or without Sigmar1 co-transfection treated with NMS-873 or chloroquine at the indicated concentration. All inhibitors were applied to cells 8 h prior to protein collection.CWestern blots showing SERCA2 expression in BMMs treated with dimemorfan or vehicle for 48 h. Eeyarestatin I was added 8 h prior to cell harvest at indicated concentration.DHEK-293T cells were transfected with different truncated SERCA2 lysine mutants and Sigmar1 and then subjected to western blot analysis.ESequence alignment of Ub sites in SERCA2 orthologs of different species. Data information: All results are representative data generated from at least three independent experiments. Source data are available online for this figure.

Fig 5: Silencing of FR229754 markedly reduced BiP levels. (a–c) Real-time PCR analysis of FR229754, Sel1l and BiP in the DMSO and tunicamycin-treated MEFs, transfected with negative control non-targeting (NT) and two small interfering (si-1 and si-2) RNAs designed against FR229754. Note that si-2 is more potent in silencing FR229754 in the MEFs. All examined RNAs were normalized to Gapdh. Data are shown as mean + SD. *P < 0.05, **P < 0.01 and ***P < 0.001. n = 3.