Journal: Autophagy
Article Title: HSF1 stress response pathway regulates autophagy receptor SQSTM1/p62-associated proteostasis
doi: 10.1080/15548627.2016.1248018
Figure Lengend Snippet: Identification of a novel kinase that phosphorylates SQSTM1 (S349). (A) HeLa cells were treated with rapamycin (MTORC1 inhibitor, 1 µM), CKI-7 (CSNK1 and SGK inhibitor, 100 µM), TBCA (CSNK2 inhibitor, 25 µM), rapamycin and CKI-7, or rapamycin and TBCA, together with MG132 (10 µM). Cell lysates were subjected to immunoblot analysis after 12 h. Band intensities were measured, and phosphorylated-SQSTM1 values were normalized to total SQSTM1. The data are reported as means ± SD ( n = 4). Statistical analyses were performed using one-way ANOVA, followed by the Tukey post-hoc test. * P < 0.01. (B) The dual and triple combination treatments of kinase inhibitors were further examined as described in A. Band intensities of S349-phosphorylated SQSTM1 were measured, and the data are reported as means ± SD ( n = 4). Statistical analyses were performed using one-way ANOVA, followed by the Tukey post-hoc test. * P < 0.01. (C) Immunoprecipitates of SQSTM1-mycHis (WT, S349A, and S403A) were incubated with CSNK1 or CSNK2 for 1 h, followed by immunoblot analysis using anti-phosphorylated SQSTM1 (p-SQSTM1 [S349] and p-SQSTM1 [S403]) and anti-SQSTM1 antibodies. (D) Colocalization of SQSTM1 with ubiquitinated inclusions was examined when SQSTM1 (S349)-phosphorylation was inhibited by the treatment with kinase inhibitors (1 µM rapamycin, 100 µM CKI-7, and 25 µM TBCA). Immunocytochemical analysis was performed 12 h after treatment. Cell nuclei were counterstained blue with DAPI. Scale bar: 10 μm.
Article Snippet: A reaction buffer containing 1 mM ATP was added to immunoprecipitation products, and then the mixtures were incubated with or without 1000 units of CSNK1 (New England Biolabs, P6030S) or 500 units of CSNK2 (New England Biolabs, P6010S) for 1 h at 37°C.
Techniques: Western Blot, Incubation