Biology:RELB
Generic protein structure example |
Transcription factor RelB is a protein that in humans is encoded by the RELB gene.[1]
Interactions
RELB has been shown to interact with NFKB2,[2][3] NFKB1,[2] and C22orf25.[4]
Activation and function
In resting cells, RelB is sequestered by the NF-κB precursor protein p100 in the cytoplasm. A select set of TNF-R superfamily members, including lymphotoxin β-receptor (LTβR), BAFF-R, CD40 and RANK, activate the non-canonical NF-κB pathway. In this pathway, NIK stimulates the processing of p100 into p52, which in association with RelB appears in the nucleus as RelB:p52 NF-κB heterodimers. RelB:p52 activates the expression homeostatic lymphokines,[5] which instruct lymphoid organogenesis and determine the trafficking of naive lymphocytes in the secondary lymphoid organs.
Recent studies has suggested that the functional non-canonical NF-κB pathway is modulated by canonical NF-κB signalling. For example, syntheses of the constituents of the non-canonical pathway, viz RelB and p52, are controlled by canonical IKK2-IκB-RelA:p50 signalling.[6] Moreover, generation of canonical and non-canonical dimers, viz RelA:p50 and RelB:p52, within the cellular milieu are mechanistically interlinked. These analyses suggest that an integrated NF-κB system network underlies activation of both RelA and RelB containing dimer and that a malfunctioning canonical pathway will lead to an aberrant cellular response also through the non-canonical pathway.
Most intriguingly, a recent study identified that TNF-induced canonical signalling subverts non-canonical RelB:p52 activity in the inflamed lymphoid tissues limiting lymphocyte ingress.[7] Mechanistically, TNF inactivated NIK in LTβR‐stimulated cells and induced the synthesis of Nfkb2 mRNA encoding p100; these together potently accumulated unprocessed p100, which attenuated the RelB activity. A role of p100/Nfkb2 in dictating lymphocyte ingress in the inflamed lymphoid tissue may have broad physiological implications.
See also
References
- ↑ "A novel mitogen-inducible gene product related to p50/p105-NF-kappa B participates in transactivation through a kappa B site". Molecular and Cellular Biology 12 (2): 685–95. February 1992. doi:10.1128/MCB.12.2.685. PMID 1531086.
- ↑ 2.0 2.1 "A physical and functional map of the human TNF-alpha/NF-kappa B signal transduction pathway". Nature Cell Biology 6 (2): 97–105. February 2004. doi:10.1038/ncb1086. PMID 14743216.
- ↑ "Activation of nuclear factor-kappaB p50 homodimer/Bcl-3 complexes in nasopharyngeal carcinoma". Cancer Research 63 (23): 8293–301. December 2003. PMID 14678988.
- ↑ "Molecular Interaction Database". http://mint.bio.uniroma2.it/mint/Welcome.do.
- ↑ "Activation of IKKalpha target genes depends on recognition of specific kappaB binding sites by RelB:p52 dimers". The EMBO Journal 23 (21): 4202–10. October 2004. doi:10.1038/sj.emboj.7600391. PMID 15470505.
- ↑ "Generation and activation of multiple dimeric transcription factors within the NF-kappaB signaling system". Molecular and Cellular Biology 28 (10): 3139–50. May 2008. doi:10.1128/MCB.01469-07. PMID 18299388.
- ↑ "A TNF-p100 pathway subverts noncanonical NF-κB signaling in inflamed secondary lymphoid organs". The EMBO Journal 36 (23): 3501–3516. December 2017. doi:10.15252/embj.201796919. PMID 29061763.
Further reading
- "TAR-independent transactivation by Tat in cells derived from the CNS: a novel mechanism of HIV-1 gene regulation". The EMBO Journal 11 (9): 3395–403. September 1992. doi:10.1002/j.1460-2075.1992.tb05418.x. PMID 1505523.
- "I-Rel: a novel rel-related protein that inhibits NF-kappa B transcriptional activity". Genes & Development 6 (5): 745–60. May 1992. doi:10.1101/gad.6.5.745. PMID 1577270.
- "Specific NF-kappa B subunits act in concert with Tat to stimulate human immunodeficiency virus type 1 transcription". Journal of Virology 66 (6): 3883–7. June 1992. doi:10.1128/JVI.66.6.3883-3887.1992. PMID 1583734.
- "A Tat-induced auto-up-regulatory loop for superactivation of the human immunodeficiency virus type 1 promoter". Journal of Virology 69 (12): 7437–44. December 1995. doi:10.1128/JVI.69.12.7437-7444.1995. PMID 7494249.
- "In vitro and in vivo binding of human immunodeficiency virus type 1 Tat protein and Sp1 transcription factor". Journal of Virology 67 (10): 6224–33. October 1993. doi:10.1128/JVI.67.10.6224-6233.1993. PMID 7690421.
- "Absolute dependence on kappa B responsive elements for initiation and Tat-mediated amplification of HIV transcription in blood CD4 T lymphocytes". The EMBO Journal 14 (7): 1552–60. April 1995. doi:10.1002/j.1460-2075.1995.tb07141.x. PMID 7729429.
- "Different members of the Sp1 multigene family exert opposite transcriptional regulation of the long terminal repeat of HIV-1". Nucleic Acids Research 22 (23): 4914–21. November 1994. doi:10.1093/nar/22.23.4914. PMID 7800480.
- "A CNS-enriched factor that binds to NF-kappa B and is required for interaction with HIV-1 tat". Oncogene 10 (2): 395–400. January 1995. PMID 7838536.
- "HIV-1 Tat potentiates TNF-induced NF-kappa B activation and cytotoxicity by altering the cellular redox state". The EMBO Journal 14 (3): 546–54. February 1995. doi:10.1002/j.1460-2075.1995.tb07030.x. PMID 7859743.
- "The expression of the interleukin 6 gene is induced by the human immunodeficiency virus 1 TAT protein". The Journal of Experimental Medicine 179 (3): 961–71. March 1994. doi:10.1084/jem.179.3.961. PMID 8113688.
- "Human RelB (I-Rel) functions as a kappa B site-dependent transactivating member of the family of Rel-related proteins". Oncogene 9 (6): 1699–702. June 1994. PMID 8183565.
- "The human NFKB3 gene encoding the p65 subunit of transcription factor NF-kappa B is located on chromosome 11q12". Genomics 19 (3): 592–4. February 1994. doi:10.1006/geno.1994.1115. PMID 8188306.
- "Human immunodeficiency virus type 1 Tat upregulates interleukin-2 secretion in activated T cells". Journal of Virology 68 (7): 4177–85. July 1994. doi:10.1128/JVI.68.7.4177-4185.1994. PMID 8207793.
- "Both N- and C-terminal domains of RelB are required for full transactivation: role of the N-terminal leucine zipper-like motif". Molecular and Cellular Biology 13 (3): 1572–82. March 1993. doi:10.1128/MCB.13.3.1572. PMID 8441398.
- "Differential effects of I kappa B molecules on Tat-mediated transactivation of HIV-1 LTR". Virology 216 (1): 284–7. February 1996. doi:10.1006/viro.1996.0062. PMID 8615004.
- "Extracellular human immunodeficiency virus type 1 Tat protein is associated with an increase in both NF-kappa B binding and protein kinase C activity in primary human astrocytes". Journal of Virology 70 (3): 1384–9. March 1996. doi:10.1128/JVI.70.3.1384-1389.1996. PMID 8627654.
- "Activation of transcription factor NF-kappaB by the Tat protein of human immunodeficiency virus type 1". Journal of Virology 70 (7): 4427–37. July 1996. doi:10.1128/JVI.70.7.4427-4437.1996. PMID 8676466.
- "Transdominant mutants of I kappa B alpha block Tat-tumor necrosis factor synergistic activation of human immunodeficiency virus type 1 gene expression and virus multiplication". Journal of Virology 70 (9): 5777–85. September 1996. doi:10.1128/JVI.70.9.5777-5785.1996. PMID 8709193.
- "Enhanced nuclear factor-kappa B activation induced by tumour necrosis factor-alpha in stably tat-transfected cells is associated with the presence of cell-surface-bound Tat protein". AIDS 10 (5): 455–61. May 1996. doi:10.1097/00002030-199605000-00002. PMID 8724035.
Original source: https://en.wikipedia.org/wiki/RELB.
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