| Structural highlights
Function
[DUS26_HUMAN] Inactivates MAPK1 and MAPK3 which leads to dephosphorylation of heat shock factor protein 4 and a reduction in its DNA-binding activity. Inhibits MAP kinase p38 by dephosphorylating it and inhibits p38-mediated apoptosis in anaplastic thyroid cancer cells. Can also induce activation of MAP kinase p38 and c-Jun N-terminal kinase (JNK).[1] [2] [3] [4]
Publication Abstract from PubMed
Regulation of p53 phosphorylation is critical to control its stability and biological activity. Dual-specificity phosphatase 26 (DUSP26) is a brain phosphatase highly overexpressed in neuroblastoma, which has been implicated in dephosphorylating phospho-Ser20 and phospho-Ser37 in the p53 transactivation domain. In this paper, we report the 1.68 A crystal structure of a catalytically inactive mutant (Cys152Ser) of DUSP26 lacking the first 60 N-terminal residues (DeltaN60-C/S-DUSP26). This structure reveals the architecture of a dual-specificity phosphatase domain related in structure to Vaccinia virus VH1. DUSP26 adopts a closed conformation of the protein tyrosine phosphatase (PTP)-binding loop, which results in an unusually shallow active site pocket and buried catalytic cysteine. A water molecule trapped inside the PTP-binding loop makes close contacts both with main chain and with side chain atoms. The hydrodynamic radius (R(H)) of DeltaN60-C/S-DUSP26 measured from velocity sedimentation analysis (R(H) approximately 22.7 A) and gel filtration chromatography (R(H) approximately 21.0 A) is consistent with an approximately 18 kDa globular monomeric protein. Instead in crystal, DeltaN60-C/S-DUSP26 is more elongated (R(H) approximately 37.9 A), likely because of the extended conformation of C-terminal helix alpha9, which swings away from the phosphatase core to generate a highly basic surface. As in the case of phosphatase MKP-4, we propose that a substrate-induced conformational change, possibly involving rearrangement of helix alpha9 with respect to the phosphatase core, allows DUSP26 to adopt a catalytically active conformation. The structural characterization of DUSP26 presented in this paper provides the first atomic insight into this disease-associated phosphatase.
Atomic Structure of Dual-Specificity Phosphatase 26, a Novel p53 Phosphatase.,Lokareddy RK, Bhardwaj A, Cingolani G Biochemistry. 2013 Jan 18. PMID:23298255[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Vasudevan SA, Skoko J, Wang K, Burlingame SM, Patel PN, Lazo JS, Nuchtern JG, Yang J. MKP-8, a novel MAPK phosphatase that inhibits p38 kinase. Biochem Biophys Res Commun. 2005 May 6;330(2):511-8. PMID:15796912 doi:10.1016/j.bbrc.2005.03.028
- ↑ Yu W, Imoto I, Inoue J, Onda M, Emi M, Inazawa J. A novel amplification target, DUSP26, promotes anaplastic thyroid cancer cell growth by inhibiting p38 MAPK activity. Oncogene. 2007 Feb 22;26(8):1178-87. Epub 2006 Aug 21. PMID:16924234 doi:10.1038/sj.onc.1209899
- ↑ Takagaki K, Shima H, Tanuma N, Nomura M, Satoh T, Watanabe M, Kikuchi K. Characterization of a novel low-molecular-mass dual specificity phosphatase-4 (LDP-4) expressed in brain. Mol Cell Biochem. 2007 Feb;296(1-2):177-84. Epub 2006 Sep 26. PMID:17001450 doi:10.1007/s11010-006-9313-5
- ↑ Hu Y, Mivechi NF. Association and regulation of heat shock transcription factor 4b with both extracellular signal-regulated kinase mitogen-activated protein kinase and dual-specificity tyrosine phosphatase DUSP26. Mol Cell Biol. 2006 Apr;26(8):3282-94. PMID:16581800 doi:26/8/3282
- ↑ Lokareddy RK, Bhardwaj A, Cingolani G. Atomic Structure of Dual-Specificity Phosphatase 26, a Novel p53 Phosphatase. Biochemistry. 2013 Jan 18. PMID:23298255 doi:10.1021/bi301476m
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