B-Cell Receptor-Associated Protein 31 Regulates the Expression of Valosin-Containing Protein Through Elf2

Abstract

Background/Aims: B-cell receptor-associated protein 31 (Bap31) is an evolutionarily conserved, ubiquitously expressed, polytopic integral membrane protein in the endoplasmic reticulum (ER) that is involved in the regulation of apoptosis, protein transport and degradation. Patients with Bap31 mutations exhibit symptoms similar to those exhibited by patients with central nervous system (CNS) diseases, such as deafness, dystonia, and intellectual disability. The present study aimed to investigate the function of Bap31 in CNS diseases by identifying a CNS disease-related gene regulated by Bap31 and exploring the underlying molecular mechanism. Methods: ShRNA-Bap31 and siRNA-Bap31 were used to knockdown Bap31 in N₂a cells, and real-time PCR was performed to detect the mRNA levels of genes involved in CNS diseases. Western blot analyses were used to examine the protein levels of the candidate gene (valosin-containing protein, VCP) both in vivo and in vitro. The functions of Bap31 and VCP in mediating the degradation of the hyper-unstable mutant of cystic fibrosis trans-membrane conductance regulator (CFTRΔF508) were studied. Moreover, real-time PCR, Western blot and dual luciferase reporter analyses were conducted to investigate the molecular mechanism by which Bap31 regulates the expression levels of VCP. Results: VCP was identified as a candidate gene based on its differential expression in N₂a cells following both shRNA- and siRNA-mediated knockdown of Bap31. Both the mRNA and protein levels of VCP were regulated by Bap31 in vivo and in vitro. In the ER-associated degradation (ERAD) pathway, Bap31 also regulated VCP expression and caused differences in the binding quantities of CFTRΔF508 and VCP. Furthermore, a transcription factor of VCP (E74-like factor 2, Elf2) was regulated by Bap31, and Elf2 mediated the changes in VCP transcription and expression in cells with altered Bap31 expression. Conclusion: These results indicate that Bap31 regulates the expression of VCP possibly via Elf2 and support the potential molecular function of Bap31 in CNS diseases.

B-Cell Receptor-Associated Protein 31 Negatively Regulates the Expression of Monoamine Oxidase A Via R1

“…The conditional knockout of BAP31 in hepatocyte promotes SREBP1C activation and hepatic lipid accumulation and worsens insulin resistance in HFD-induced obesity in mice (Xu et al, 2018). Bap31 regulates the expression of VCP via its transcription factor Elf2 (Jia et al, 2018). However, there is still little research on the biological function of Bap31.…”

“…Bap31, as an important member of the ER-associated degradation (ERAD) (Wakana et al, 2008), promotes the mutant of cystic fibrosis transmembrane regulator (CFTR F508) to degradation via the Derlin1 complex (Wang et al, 2008). Our former study demonstrates that Bap31 regulates one of the central nervous system disease-related gene (valosin-containing protein, VCP) expression (Jia et al, 2018). Moreover, the contiguous deletion of ABCD1 DXS1357E (Bap31) leads to X-linked syndromes (Corzo et al, 2002;Iwasa et al, 2013).…”

Quantitative proteomic analyses reveal the dynamics of protein and amino acid accumulation during soybean seed development

“…However, the functions of this protein were well studied in mammalian systems and microbial systems [16,17]. In the mammalian system, it involves protein sorting, transport, signalling, degradation, phosphorylation, and methylation [18,19]. Interaction of this protein with transcription factor 2 (elf2) is also reported [19].…”

Regulation of Superoxide by BAP31 through Its Effect on p22phox and Keap1/Nrf2/HO‐1 Signaling Pathway in Microglia

“…MDA formation was measured at 532 nm, and results were expressed as nmol of MDA/mg of protein. 20]. PCR primers for p22 phox (Cyba), p40 phox (Ncf4), p47 phox (Ncf1), p67 phox (Ncf2), gp91 phox (Cybb), IL-1β, TNFα, CD80, CD86, Arg1, CD206, Fizz1, Ym1, and GAPDH were designed as follows: p22 phox (Cyba) primer, sense 5′ -GTGTGCTCATCTGTCTGCTG-3′, antisense 5′-TGGG TTTAGGCTCAATGGGA-3′; p40 phox (Ncf4) primer, sense 5′-TCTCATCTACCGCCGCTATC-3′, antisense 5′-CCAT GTAGACTTTGGCTGGC-3 ′ ; p47 phox (Ncf1) primer, sense 5 ′ -TGCCAGA TGAAGACAAAGCG-3 ′ , antisense 5 ′ -TTCACCTGCGTAGTTGGGAT-3 ′ ; p67 phox (Ncf2) primer, sense 5 ′ -ACCGCGTATTGTTTGGCTTT-3 ′ , antisense 5 ′ -AGCCCCTTCT GTCCATTGAA-3 ′ ; gp91 phox (Cybb) primer, sense 5 ′ -GGTTTTGGCGATCTCAGC AA-3 ′ , antisense 5 ′ -ACTGTCCCACCTCCATCTTG-3 ′ ; IL-1β primer, sense 5 ′ -TGACGGACCCCAAAAGATGA-3 ′ , antisense 5 ′ -TCTCCACAGCCACAATGA GT-3 ′ ; TNFα primer, sense 5 ′ -CCCTCACACTCAGATCATCTTCT-3 ′ , antisense 5 ′ 3 Oxidative Medicine and Cellular Longevity -GCTACGACGTGGGCTACAG-3 ′ ; CD80 primer, sense 5 ′ -TGGCCCGAGTATAAGA ACCG-3 ′ , antisense 5 ′ -CCGG AAGCAAAGCAGGTAAT-3 ′ ; CD86 primer, sense 5 ′ -GCACGTCTAAGCAAGGTCAC-3 ′ , antisense 5 ′ -CATA TGCCACACACCATCCG-3 ′ ; Arg1 primer, sense 5 ′ -GTCGGGAAGGAAGAAAAGGC-3 ′ , antisense 5 ′ -TGCC GT GTTCACAGTACTCT-3 ′ ; CD206 primer, sense 5 ′ -TGGATGGATGGGAGCAAAGT-3 ′ , antisense 5 ′ -GCTG CTGTTATGTCTCTGGC-3 ′ ; Fizz1 primer, sense 5 ′ -GAACTTCT TGCCAATCCAGCT-3 ′ , antisense 5 ′ -CTCC CAAGATCCACAGGCAA-3 ′ ; and Ym1 primer, sense 5 ′ -GGGTAATGAGTGGGTTGGT-3 ′ , antisense 5 ′ -CCAC GGCACCTCCTAA ATTG-3 ′ .…”