Journal: Frontiers in Physiology
Article Title: Constitutive expression of spliced X-box binding protein 1 inhibits dentin formation in mice
doi: 10.3389/fphys.2023.1319954
Figure Lengend Snippet: IRE1α activation-independent expression of XBP1S. (A, B) . Shown are the schematic representations of the Xbp1 minigene (A) and Xbp1s minigene (B) constructs. The Xbp1s minigene contains a modified exon 4 (Δ26) that lack the 26 intronic sequence, and it also contains a loxP site in intron 3. +1, the transcription start site; E, exon; green boxes, coding exons; and grey boxes, non-coding exons. AscI, NsiI, EcoRV, HindIII, SspI and AflII are restriction endonucleases. (C, D) . HEK 293 cells were transiently transfected with the Xbp1 minigene (C) or Xbp1s minigene (D) together with the pCDNA3 empty vector (Vector) (lane 3) or a construct expressing normal (Norm) IRE1α (lane 4) or two IRE1α variants, K599A (lane 5) and N906A (lane 6). HEK 293 cells were transfected with the pCDNA3 empty vector alone (lane 1) or the construct expressing normal IRE1α alone (lane 2) as controls. Total cell lysate was harvested 48 h after transfection and analyzed by Western-blotting with an antibody that recognizes both XBP1U and XBP1S, the blot was then stripped and sequentially probed with an antibody against phosphorylated IRE1α and total IRE1α. The blot was probed with mouse monoclonal β-actin antibody as the loading control.
Article Snippet: The membrane was sequentially immunoblotted with rabbit anti-XBP1 polyclonal antibody that recognizes both XBP1U and XBP1S (1:4000, Abcam, Cambridge, MA), horseradish peroxidase (HRP)-conjugated rabbit polyclonal anti-phosphorylated IRE1α (pSer724) (1:5000; Novus Biologicals) and mouse monoclonal anti-IRE1α antibody (1:1000; Santa Cruz Biotechnology, Inc.).
Techniques: Activation Assay, Expressing, Construct, Modification, Sequencing, Transfection, Plasmid Preparation, Western Blot