Fig. 2: LTK allows cells to cope with high secretory load.
From: Targeting proteostasis in multiple myeloma through inhibition of LTK
A HeLa cells expressing inducible IgM (heavy and light chain) were transfected with control or LTK siRNA. After 72 h, cells were treated with mifepristone to induce IgM expression followed by lysis and immunoblotting against the indicated proteins. B LTK mRNA is fourfold higher in HeLa cells with 2 weeks IgM expression compared to control. C Immunoblot of HeLa cells with induce IgM expression over a period of 2 weeks, subsequently treated with 1 μM crizotinib for 24 h. D L363 and bortezomib resistant L363-BTZ cells were treated with 5 µM crizotinib and the expression of spliced vs non-spliced XBP1 was not statistically different regardless of bortezomib sensitivity (p =0.533) for L363 vs L363-BTZ, two-way ANOVA (see also Supplementary Fig. S2A, B for analysis of crizotinib vs no drug for each cell line). E ATF4 was determined 4, 8 and 12 h post-treatment. Spliced vs non-spliced XBP1 p = 0.533 for L363 vs L363-BTZ, as well as ATF4 p = 0.267 between L363 and L363-BTZ and p = 0.013 for ATF4 expression over time (Supplementary Fig. S2).
