Journal: bioRxiv
Article Title: DR5 disulfide bonding as a sensor and effector of protein folding stress
doi: 10.1101/2024.03.04.583390
Figure Lengend Snippet: A variety of ER stressors alter DR5 disulfide bonding. A, upper panel. ERp44-deficient HepG2 cells into which vector, wild type or catalytically null ERp44 were reintroduced were treated as indicated for 24 h and analyzed by non-reducing immunoblot. A, lower panel. Expanded region of the DR5 immunoblot showing altered DR5 disulfide bonding in the Thapsigargin/PERKi combination treatment. B. Non-reducing immunoblot of MDA-MB-468 cells treated as indicated for 24 h. C. MDA-MB-468 cells were treated as indicated for 24 h and subjected to non-reducing (DR5, Cleaved Caspase 3, DR4, Actin) or reducing (MET) immunoblot analysis. D. Protein synthesis assays of cells pre-treated for 24 h as indicated before protein synthesis was measured by 3 H-Leucine incorporation over a 2 h pulse. Data are plotted as the average (N = 6), with error bars representing standard deviation. E. HepG2 cells were treated as indicated for 24 h and subjected to non-reducing (DR5, Cleaved Caspase 3, DR4, Actin) or reducing (MET) immunoblot analysis. F. Control and PERK knockout HepG2 cells were treated for 24 h as indicated and subjected to non-reducing immunoblot analysis. G. Non-reducing immunoblot analysis of the indicated cell lines treated as specified for 24 h. Note the DR5 oligomerization in A431 cells when Thapsigargin, Tunicamycin, or dFtcyDTDO are combined with PERK inhibition. H. Non-reducing immunoblot analysis of WM793 cells treated as specified for 24 h. Unless otherwise specified, the following concentrations of compounds were used in A-H above: dFtcyDTDO (2.5 μM), Thapsigargin (400 nM), Tunicamycin (500 ng/ml), Cyclosporine A (10 μM), Dithiothreitol (DTT; (2.5 mM)), ISRIB (200 nM), or PERKi (1μM). O and M represent Oligomeric and Monomeric protein isoforms in panels A, C, E, G, and H.
Article Snippet: In order to construct the Tet-DR4 expression vector, DR4 (Addgene plasmid #61382) was amplified using the following primers: 5′-TTTTATCGATCACCATGGCGCCCGTCGCCGTCTGG-3′ and 5′-TTTTGGATCCTCACTCCAAGGACACGGCAG-3′ and cloned into the pRetroX-TetOne-Puro vector with a modified cloning site that incorporates Not I, Bcl I, and Cla I sites 5′ to the BamH I site (Clontech, Mountain View, CA, USA).
Techniques: Plasmid Preparation, Western Blot, Standard Deviation, Control, Knock-Out, Inhibition