Journal: Cell reports
Article Title: CD44 correlates with longevity and enhances basal ATF6 activity and ER stress resistance
doi: 10.1016/j.celrep.2023.113130
Figure Lengend Snippet: (A) The heatmap shows relative abundances of ER-associated proteins detected by mass spectrometry of ER fractions isolated from shLuc, shCD44–1, and shCD44–2 IMR90-hTert cells. Cells were collected 24 h after starting 0.5 μg/mL tunicamycin treatment. ER-associated proteins were defined here as the proteins whose ER localization have been confirmed by the Human Protein Atlas or associated with the GO term “endoplasmic reticulum lumen.” (B) Representative immunoblots of COL6A3, SEC62, and HSPA5 in shLuc, shCD44–1, and shCD44–2 IMR90-hTert cells. Whole cell lysates and culture supernatants were collected 24 h after starting 0.5 μg/mL tunicamycin treatment. (C) Representative immunoblots of ATF6, IRE1, PERK, CALR, EGFR, and Vinculin in shLuc, shCD44–1, and shCD44–2 IMR90-hTert cells. Cells were lysed in buffer containing either 1% Triton or 2% SDS. (D) A representative immunoblot of ATF6 in U2OS cells and in ATF6 KO U2OS cells infected with empty vector or vector expressing wild-type ATF6, ATF6 Y392C, or ATF6 Y567N. (E) Cell survival rate of ATF6 KO U2OS cells after 5 days of 2 μg/mL tunicamycin treatment (n = 8). Cells were infected with vector expressing wild-type ATF6, ATF6 Y392C, or ATF6 Y567N and selected with 100 μg/mL hygromycin prior to the experiment. (F) Relative expression levels of HSP90B1 and HSP5A in CD44 KO U2OS cells (n = 3). Cells were infected with empty vector or vector encoding CD44-ectodomain-KDEL 3 days before sample collection. Data were normalized to GAPDH . (G) Cell survival rate of CD44 KO U2OS cells after 5 days of 2 μg/mL tunicamycin treatment. Cells were infected with empty vector or vector encoding CD44-ectodomain-KDEL 3 days before starting tunicamycin treatment (n = 8). All immunoblots were repeated at least once with similar results. Error bars are presented as mean ± SD values. *p < 0.05; two-way ANOVA with post hoc Dunnett’s test (E) and two-tailed t test with (F) or without (G) Bonferroni-Dunn correction.
Article Snippet: Vectors encoding human ATF6 and S1P site-mutated GFP-ATF6 were obtained from Addgene (#11974 and #32956)., Mouse standard form CD44, mouse LDLR, and NMR standard form CD44 were cloned in pBabe-hygro vector (Addgene #1765).
Techniques: Mass Spectrometry, Isolation, Western Blot, Infection, Plasmid Preparation, Expressing, Two Tailed Test