recombinant grp78 protein (Boster Bio)
Structured Review

Recombinant Grp78 Protein, supplied by Boster Bio, used in various techniques. Bioz Stars score: 92/100, based on 1 PubMed citations. ZERO BIAS - scores, article reviews, protocol conditions and more
https://www.bioz.com/product/recombinant+grp78+protein/pmc10701780-99-4-8?v=Boster+Bio
Average 92 stars, based on 1 article reviews
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1) Product Images from "The synthetic oleanane triterpenoid CDDO‐2P‐Im binds GRP78 / BiP to induce unfolded protein response‐mediated apoptosis in myeloma"
Article Title: The synthetic oleanane triterpenoid CDDO‐2P‐Im binds GRP78 / BiP to induce unfolded protein response‐mediated apoptosis in myeloma
Journal: Molecular Oncology
doi: 10.1002/1878-0261.13447
Figure Legend Snippet: CDDO‐2P‐Im binds GRP78 and activates the PERK and IRE1α branches of the UPR in a dose‐dependent manner. (A) Cell lysate of RPMI‐8226 was incubated with DMSO or CDDO‐2P‐Im for 30 min. Lysates were then subjected to 0.025 mg·mL −1 pronase for 30 min at 4 °C, followed by SDS/PAGE and western blot using antibodies against GRP78 and GAPDH. CDDO‐2P‐Im protects GRP78 from pronase cleavage compared with DMSO control. (B) Thermal shift assay was performed on recombinant GRP78 treated with control (DMSO) or CDDO‐2P‐Im. Relative fluorescent units (RFU) were measured by a SpectraMax Paradigm plate reader. The melting temperature (Tm) has a shift of −1.9 °C with the treatment of CDDO‐2P‐Im. (C, D) ARH‐77 and RPMI‐8226 cells were incubated with CDDO‐2P‐Im for 6 h. Cells were lysed and samples were prepared for SDS/PAGE. Western blot of UPR signaling proteins and downstream targets were performed. (E) 5T33 tumors were extracted from mice 15 days after tumor injection. Mice were treated once with either vehicle or 24 mg·kg −1 CDDO‐2P‐Im for 12 h prior to extraction. Samples were immunoblotted for UPR proteins. (F) RNA‐Sequencing data for ATF6 regulated genes showed no differences between Control, 0.1 μ m CDDO‐2P‐Im, and 0.4 μ m CDDO‐2P‐Im in RPMI‐8226 cells. (G, H) Western blot of ATF6 in ARH‐77 and RPMI‐8226 show no changes at 6 h with the treatment of CDDO‐2P‐Im. Values were given as mean ± SD. Fragments Per Kilobase of transcript per Million mapped reads is abbreviated as FPKM. Western blot and DARTS data are representatives of at least three independent experiments for ARH‐77 cells and RPMI‐8226 cells. Thermal shift assay was performed three independent times and representative data was shown. Western blot of 5T33 tumors was performed once. RNA‐Sequencing was performed once. Student t ‐tests were performed to calculate P value. 2P‐Im, CDDO‐2P‐Im; CDDO, CDDO‐2P‐Im.
Techniques Used: Incubation, SDS Page, Western Blot, Control, Thermal Shift Assay, Recombinant, Injection, Extraction, RNA Sequencing
Figure Legend Snippet: Inhibition of the PERK‐ATF4‐CHOP arm of the UPR partially rescues CDDO‐2P‐Im‐induced apoptosis. (A) Cell lysate of WT and PERK KO RPMI‐8226 were probed for PERK protein by western blot. (B) WT and DDIT3 (CHOP) KO RPMI‐8226 were incubated with DMSO or CDDO‐2P‐Im for 6 h and lysed for protein analysis. Western blot of CHOP was performed to investigate the knockout of CHOP protein. (C) Cells were preincubated with DMSO or CDDO‐2P‐Im for 24 h and evaluated for cell viability by CellTiter‐Glo™. (D) Cells were preincubated with DMSO or 0.25 μ m ISRIB for 3 h before treating with DMSO or CDDO‐2P‐Im for an additional 16 h. Cells were then measured for cell viability by CellTiter‐Glo™. Controls were cells that were not treated with CDDO‐2P‐im but were treated with DMSO or ISRIB where appropriate. (E–H) PERK KO and WT RPMI‐8226 cells or ARH‐77 cells pretreated with ISRIB for 3 h were incubated with DMSO control or 0.4 μ m CDDO‐2P‐Im for 6 h. (E, F) Cells were extracted for RNA and qRT‐PCR was performed to investigate changes in the UPR. (G, H) In another round of experiments, cells were also extracted for protein to confirm such changes in the UPR. Values were given as mean ± SD. Student t ‐tests were performed to calculate P value. * P < 0.05 and ** P < 0.01, compared with control. Cell viability data are representative of three independent experiments. Western blots and qRT‐PCR data are representatives of two independent experiments. (I) We provide a working model of the actions of CDDO‐2P‐Im in cancer cells. At low concentrations (panel A), 2P‐Im binds and inhibits KEAP1, an adaptor protein for ubiquitin ligase that negatively regulates Nrf2 levels. Nrf2 will translocate to the nucleus and dimerize with small Maf proteins (sMaf) to activate the transcription of Nrf2 target genes. At higher concentrations (panel B), 2P‐Im binds GRP78/BiP, resulting in the activation of the UPR. GRP78 dissociates from its binding partners leading to the phosphorylation of PERK and IRE1α and activation of these branches of the UPR. The transcription factors, CHOP and XBP1, will cause UPR‐associated gene expression changes which when prolonged will lead to apoptosis. Interestingly, XBP1 is known to increase the expression of HRD1, a negative regulator of Nrf2, and independent of KEAP1. 2P/2P‐Im, CDDO‐2P‐Im; ISRIB, integrated stress response inhibitor; WT, wild‐type; KO, knockout.
Techniques Used: Inhibition, Western Blot, Incubation, Knock-Out, Control, Quantitative RT-PCR, Ubiquitin Proteomics, Activation Assay, Binding Assay, Phospho-proteomics, Gene Expression, Expressing
