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Catalytic domain of the protein kinases, Dual-specificity tYrosine-phosphorylated and -Regulated Kinases 2 and 3 Dual-specificity PKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine (S/T) as well as tyrosine residues on protein substrates. This subfamily is composed of DYRK2 and DYRK3, and similar proteins. Drosophila DYRK2 interacts and phosphorylates the chromatin remodelling factor, SNR1 (Snf5-related 1), and also interacts with the essential chromatin component, trithorax. It may play a role in chromatin remodelling. Vertebrate DYRK2 phosphorylates and regulates the tumor suppressor p53 to induce apoptosis in response to DNA damage. It can also phosphorylate the transcription factor, nuclear factor of activated T cells (NFAT). DYRK2 is overexpressed in lung adenocarcinoma and esophageal carcinomas, and is a predictor for favorable prognosis in lung adenocarcinoma. DYRK3, also called regulatory erythroid kinase (REDK), is highly expressed in erythroid cells and the testis, and is also present in adult kidney and liver. It promotes cell survival by phosphorylating and activating SIRT1, an NAD(+)-dependent protein deacetylase, which promotes p53 deacetylation, resulting in the inhibition of apoptosis. DYRKs autophosphorylate themselves on tyrosine residues and phosphorylate their substrates exclusively on S/T residues. The DYRK2/3 subfamily is part of a larger superfamily that includes the catalytic domains of other S/T kinases, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase.
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