Recombination Signal Sequence Binding Protein Jkappa is Constitutively Bound to the NF-kappaB Site of the Interleukin-6 Promoter and Acts As a Negative Regulatory Factor
Overview
Affiliations
Analysis by electrophoretic mobility shift assays (EMSA) of the different proteins associated with the kappaB sequence of the interleukin-6 (IL-6) promoter (IL6-kappaB) allowed us to detect a specific complex formed with the recombination signal sequence binding protein Jkappa (RBP-Jkappa). Single-base exchanges within the oligonucleotide sequence defined the critical base pairs involved in the interaction between RBP-Jkappa and the IL6-kappaB motif. Binding analysis suggests that the amount of RBP-Jkappa protein present in the nucleus is severalfold higher than the total amount of inducible NF-kappaB complexes but that the latter bind DNA with a 10-fold-higher affinity. A reporter gene study was performed to determine the functional implication of this binding; we found that the constitutive occupancy of the IL6-kappaB site by the RBP-Jkappa protein was responsible for the low basal levels of IL-6 promoter activity in L929sA fibrosarcoma cells and that RBP-Jkappa partially blocked access of NF-kappaB complexes to the IL-6 promoter. We propose that such a mechanism could be involved in the constitutive repression of the IL-6 gene under normal physiological conditions.
Xia Y, Inoue K, Zheng T, Qin Y, Zhao B FASEB J. 2024; 38(13):e23704.
PMID: 38884155 PMC: 11602219. DOI: 10.1096/fj.202302230R.
Intrinsic Restriction of TNF-Mediated Inflammatory Osteoclastogenesis and Bone Resorption.
Zhao B Front Endocrinol (Lausanne). 2020; 11:583561.
PMID: 33133025 PMC: 7578415. DOI: 10.3389/fendo.2020.583561.
Regulatory network mediated by RBP-J/NFATc1-miR182 controls inflammatory bone resorption.
Inoue K, Hu X, Zhao B FASEB J. 2020; 34(2):2392-2407.
PMID: 31908034 PMC: 7018544. DOI: 10.1096/fj.201902227R.
Bougarne N, Mylka V, Ratman D, Beck I, Thommis J, De Cauwer L Front Immunol. 2019; 10:1769.
PMID: 31447832 PMC: 6695567. DOI: 10.3389/fimmu.2019.01769.
Does TNF Promote or Restrain Osteoclastogenesis and Inflammatory Bone Resorption?.
Zhao B Crit Rev Immunol. 2019; 38(4):253-261.
PMID: 30806242 PMC: 6422676. DOI: 10.1615/CritRevImmunol.2018025874.