| Structural highlights
Function
[TXNIP_HUMAN] May act as an oxidative stress mediator by inhibiting thioredoxin activity or by limiting its bioavailability. Interacts with COPS5 and restores COPS5-induced suppression of CDKN1B stability, blocking the COPS5-mediated translocation of CDKN1B from the nucleus to the cytoplasm. Functions as a transcriptional repressor, possibly by acting as a bridge molecule between transcription factors and corepressor complexes, and over-expression will induce G0/G1 cell cycle arrest. Required for the maturation of natural killer cells. Acts as a suppressor of tumor cell growth. Inhibits the proteasomal degradation of DDIT4, and thereby contributes to the inhibition of the mammalian target of rapamycin complex 1 (mTORC1).[1] [2] [3] [4] [THIO_HUMAN] Participates in various redox reactions through the reversible oxidation of its active center dithiol to a disulfide and catalyzes dithiol-disulfide exchange reactions. Plays a role in the reversible S-nitrosylation of cysteine residues in target proteins, and thereby contributes to the response to intracellular nitric oxide. Nitrosylates the active site Cys of CASP3 in response to nitric oxide (NO), and thereby inhibits caspase-3 activity. Induces the FOS/JUN AP-1 DNA-binding activity in ionizing radiation (IR) cells through its oxidation/reduction status and stimulates AP-1 transcriptional activity.[5] [6] [7] [8] [9] ADF augments the expression of the interleukin-2 receptor TAC (IL2R/P55).[10] [11] [12] [13] [14]
Publication Abstract from PubMed
The redox-dependent inhibition of thioredoxin (TRX) by thioredoxin-interacting protein (TXNIP) plays a pivotal role in various cancers and metabolic syndromes. However, the molecular mechanism of this regulation is largely unknown. Here, we present the crystal structure of the TRX-TXNIP complex and demonstrate that the inhibition of TRX by TXNIP is mediated by an intermolecular disulphide interaction resulting from a novel disulphide bond-switching mechanism. Upon binding to TRX, TXNIP undergoes a structural rearrangement that involves switching of a head-to-tail interprotomer Cys63-Cys247 disulphide between TXNIP molecules to an interdomain Cys63-Cys190 disulphide, and the formation of a de novo intermolecular TXNIP Cys247-TRX Cys32 disulphide. This disulphide-switching event unexpectedly results in a domain arrangement of TXNIP that is entirely different from those of other arrestin family proteins. We further show that the intermolecular disulphide bond between TRX and TXNIP dissociates in the presence of high concentrations of reactive oxygen species. This study provides insight into TRX and TXNIP-dependent cellular regulation.
The structural basis for the negative regulation of thioredoxin by thioredoxin-interacting protein.,Hwang J, Suh HW, Jeon YH, Hwang E, Nguyen LT, Yeom J, Lee SG, Lee C, Kim KJ, Kang BS, Jeong JO, Oh TK, Choi I, Lee JO, Kim MH Nat Commun. 2014 Jan 6;5:2958. doi: 10.1038/ncomms3958. PMID:24389582[15]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Liyanage NP, Fernando MR, Lou MF. Regulation of the bioavailability of thioredoxin in the lens by a specific thioredoxin-binding protein (TBP-2). Exp Eye Res. 2007 Aug;85(2):270-9. Epub 2007 May 21. PMID:17603038 doi:S0014-4835(07)00133-9
- ↑ Han SH, Jeon JH, Ju HR, Jung U, Kim KY, Yoo HS, Lee YH, Song KS, Hwang HM, Na YS, Yang Y, Lee KN, Choi I. VDUP1 upregulated by TGF-beta1 and 1,25-dihydorxyvitamin D3 inhibits tumor cell growth by blocking cell-cycle progression. Oncogene. 2003 Jun 26;22(26):4035-46. PMID:12821938 doi:10.1038/sj.onc.1206610
- ↑ Shin KH, Kim RH, Kim RH, Kang MK, Park NH. hnRNP G elicits tumor-suppressive activity in part by upregulating the expression of Txnip. Biochem Biophys Res Commun. 2008 Aug 8;372(4):880-5. doi:, 10.1016/j.bbrc.2008.05.175. Epub 2008 Jun 9. PMID:18541147 doi:10.1016/j.bbrc.2008.05.175
- ↑ Jin HO, Seo SK, Kim YS, Woo SH, Lee KH, Yi JY, Lee SJ, Choe TB, Lee JH, An S, Hong SI, Park IC. TXNIP potentiates Redd1-induced mTOR suppression through stabilization of Redd1. Oncogene. 2011 Sep 1;30(35):3792-801. doi: 10.1038/onc.2011.102. Epub 2011 Apr 4. PMID:21460850 doi:10.1038/onc.2011.102
- ↑ Jacquot JP, de Lamotte F, Fontecave M, Schurmann P, Decottignies P, Miginiac-Maslow M, Wollman E. Human thioredoxin reactivity-structure/function relationship. Biochem Biophys Res Commun. 1990 Dec 31;173(3):1375-81. PMID:2176490
- ↑ Hirota K, Matsui M, Iwata S, Nishiyama A, Mori K, Yodoi J. AP-1 transcriptional activity is regulated by a direct association between thioredoxin and Ref-1. Proc Natl Acad Sci U S A. 1997 Apr 15;94(8):3633-8. PMID:9108029
- ↑ Wei SJ, Botero A, Hirota K, Bradbury CM, Markovina S, Laszlo A, Spitz DR, Goswami PC, Yodoi J, Gius D. Thioredoxin nuclear translocation and interaction with redox factor-1 activates the activator protein-1 transcription factor in response to ionizing radiation. Cancer Res. 2000 Dec 1;60(23):6688-95. PMID:11118054
- ↑ Mitchell DA, Marletta MA. Thioredoxin catalyzes the S-nitrosation of the caspase-3 active site cysteine. Nat Chem Biol. 2005 Aug;1(3):154-8. Epub 2005 Jul 10. PMID:16408020 doi:http://dx.doi.org/nchembio720
- ↑ Mitchell DA, Morton SU, Fernhoff NB, Marletta MA. Thioredoxin is required for S-nitrosation of procaspase-3 and the inhibition of apoptosis in Jurkat cells. Proc Natl Acad Sci U S A. 2007 Jul 10;104(28):11609-14. Epub 2007 Jul 2. PMID:17606900 doi:http://dx.doi.org/0704898104
- ↑ Jacquot JP, de Lamotte F, Fontecave M, Schurmann P, Decottignies P, Miginiac-Maslow M, Wollman E. Human thioredoxin reactivity-structure/function relationship. Biochem Biophys Res Commun. 1990 Dec 31;173(3):1375-81. PMID:2176490
- ↑ Hirota K, Matsui M, Iwata S, Nishiyama A, Mori K, Yodoi J. AP-1 transcriptional activity is regulated by a direct association between thioredoxin and Ref-1. Proc Natl Acad Sci U S A. 1997 Apr 15;94(8):3633-8. PMID:9108029
- ↑ Wei SJ, Botero A, Hirota K, Bradbury CM, Markovina S, Laszlo A, Spitz DR, Goswami PC, Yodoi J, Gius D. Thioredoxin nuclear translocation and interaction with redox factor-1 activates the activator protein-1 transcription factor in response to ionizing radiation. Cancer Res. 2000 Dec 1;60(23):6688-95. PMID:11118054
- ↑ Mitchell DA, Marletta MA. Thioredoxin catalyzes the S-nitrosation of the caspase-3 active site cysteine. Nat Chem Biol. 2005 Aug;1(3):154-8. Epub 2005 Jul 10. PMID:16408020 doi:http://dx.doi.org/nchembio720
- ↑ Mitchell DA, Morton SU, Fernhoff NB, Marletta MA. Thioredoxin is required for S-nitrosation of procaspase-3 and the inhibition of apoptosis in Jurkat cells. Proc Natl Acad Sci U S A. 2007 Jul 10;104(28):11609-14. Epub 2007 Jul 2. PMID:17606900 doi:http://dx.doi.org/0704898104
- ↑ Hwang J, Suh HW, Jeon YH, Hwang E, Nguyen LT, Yeom J, Lee SG, Lee C, Kim KJ, Kang BS, Jeong JO, Oh TK, Choi I, Lee JO, Kim MH. The structural basis for the negative regulation of thioredoxin by thioredoxin-interacting protein. Nat Commun. 2014 Jan 6;5:2958. doi: 10.1038/ncomms3958. PMID:24389582 doi:http://dx.doi.org/10.1038/ncomms3958
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