Journal: The American Journal of Pathology
Article Title: Formaldehyde Is a Potent Proteotoxic Stressor Causing Rapid Heat Shock Transcription Factor 1 Activation and Lys48-Linked Polyubiquitination of Proteins
doi: 10.1016/j.ajpath.2016.06.022
Figure Lengend Snippet: Formation of polyubiquitinated proteins in FA-treated H460 human lung cells. A: Representative images of cells stained for DNA (DAPI), S-phase cells (EdU), and polyubiquitinated proteins (FK2 antibody). Cells were treated with FA for 3 hours in complete medium. B: Immunostaining for K48-Ub in FA-treated (3 hours) and heat-shocked cells. C: Cell viability and colony formation after FA treatments. Viability was measured at 72 hours after FA exposure. D: Formation of K48-Ub by FA and MG132 (5 μmol/L). Tubulin is used as a loading control. E: Western blot analysis for K63-specific polyubiquitination of soluble proteins in cells treated with FA and the deubiquitinase inhibitor G5. F: Western blot analysis for K63-Ub in the insoluble cellular proteins. Fibrillarin was used as a loading control. Data are expressed as means ± SD. n = 2 independent experiments, each including three dishes (clonogenic survival) or four wells (viability assay) per dose (C). EdU, 5-ethynyl-2′-deoxyuridine; FA, formaldehyde; K48-Ub, K48-linked polyubiquitin; K63-Ub, K63-polyubiquitination.
Article Snippet: Primary antibodies for K48-linked polyubiquitin (05-61307; Millipore), K63-linked polyubiquitin (BML-PW0600; Enzo, Farmingdale, NY), phospho-S326-HSF1 (ab76076; Abcam), HSF1 (4356; Cell Signaling Technology), FK2 (BML-PW8810; Enzo), HSP72/73 (HSP01, Millipore) were all used at 1:200 dilution.
Techniques: Staining, Immunostaining, Western Blot, Viability Assay