Molecular Cloning and Characterization of a Novel Dual-specificity Protein Phosphatase Possibly Involved in Spermatogenesis
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Dual-specificity protein phosphatases (DSPs) play roles in the regulation of mitogenic signal transduction for extracellular stimulation and the cell cycle. In the present study, we identified a novel DSP, termed TMDP (testis- and skeletal-muscle-specific DSP). Nucleotide sequence analysis of TMDP cDNA indicated that the open reading frame of 597 bp encodes a protein of 198 amino acid residues with a predicted molecular mass of 22.5 kDa. The deduced amino acid sequence contains a motif for a conserved catalytic domain of DSPs and shows highest similarity to human Vaccinia HI-related phosphatase (45.5% identity) but low homology to the mitogen-activated protein kinase phosphatase and CDC25 subfamilies of DSPs. Recombinant TMDP protein exhibited intrinsic phosphatase activity towards both phospho-seryl/threonyl and -tyrosyl residues of myelin basic protein, with similar specific activities in vitro. Northern-blot analysis revealed that TMDP is most abundantly expressed in the testis. The expression in the testis is characterized as follows: (i) TMDP mRNA first appeared 3 weeks after birth, corresponding to the time that meiosis begins; (ii) TMDP mRNA was abundant in fractionated spermatocytes and round spermatids; and (iii) hybridization in situ showed that the TMDP mRNA is localized in spermatocytes and/or spermatids in seminiferous tubules. These data demonstrate that TMDP is a novel DSP abundantly expressed in the testis and suggest that TMDP may be involved in the regulation of meiosis and/or differentiation of testicular germ cells during spermatogenesis.
Krzesniak M, Lasut-Szyszka B, Bedzinska A, Gdowicz-Klosok A, Rusin M Biomedicines. 2024; 12(7).
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Inhibition of peptide aggregation by means of enzymatic phosphorylation.
Folmert K, Broncel M, Berlepsch H, Ullrich C, Siegert M, Koksch B Beilstein J Org Chem. 2017; 12:2462-2470.
PMID: 28144314 PMC: 5238555. DOI: 10.3762/bjoc.12.240.
DUSP13B/TMDP inhibits stress-activated MAPKs and suppresses AP-1-dependent gene expression.
Katagiri C, Masuda K, Nomura M, Tanoue K, Fujita S, Yamashita Y Mol Cell Biochem. 2011; 352(1-2):155-62.
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Takagaki K, Shima H, Tanuma N, Nomura M, Satoh T, Watanabe M Mol Cell Biochem. 2006; 296(1-2):177-84.
PMID: 17001450 DOI: 10.1007/s11010-006-9313-5.