Adults with Down syndrome (DS) develop Alzheimer neurofibrillary degeneration in the brain, but the underlying molecular mechanism is unknown. Here, we report that the presence of an extra copy of the dual-specificity tyrosine-phosphorylated and regulated kinase 1A (Dyrk1A) gene due to trisomy 21 resulted in overexpression of Dyrk1A and elevated kinase activity in DS brain. Dyrk1A phosphorylated tau at several sites, and these sites were hyperphosphorylated in adult DS brains. Phosphorylation of tau by Dyrk1A primed its further phosphorylation by glycogen synthase kinase-3beta (GSK-3beta). Dyrk1A-induced tau phosphorylation inhibited tau's biological activity and promoted its self-aggregation. In Ts65Dn mouse brain, an extra copy of the Dyrk1A gene caused increased expression and activity of Dyrk1A and resulted in increased tau phosphorylation. These findings strongly suggest a novel mechanism by which the overexpression of Dyrk1A in DS brain causes neurofibrillary degeneration via hyperphosphorylating tau.
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http://dx.doi.org/10.1096/fj.07-104539 | DOI Listing |
Int J Biol Macromol
December 2024
Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan; Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan; TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, Taiwan. Electronic address:
Alzheimer's disease (AD) is an irreversible neurodegenerative disease, with tau pathology caused by abnormally activated dual-specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A) being one of the culprits. Coumestrol, a phytoestrogen and natural antioxidant found in various plants, has been reported to alleviate AD, but the underlying mechanism remains unclear. We confirmed coumestrol as a novel DYRK1A inhibitor through enzyme-based assays, X-ray crystallography, and cell line experiments.
View Article and Find Full Text PDFElife
October 2024
State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China.
DYRK1A, a ubiquitously expressed kinase is linked to the dominant intellectual developmental disorder, microcephaly, and Down syndrome in humans. It regulates numerous cellular processes such as cell cycle, vesicle trafficking, and microtubule assembly. DYRK1A is a critical regulator of organ growth; however, how it regulates organ growth is not fully understood.
View Article and Find Full Text PDFJ Alzheimers Dis
October 2024
Initial R&D Consulting, Paris, France.
Alzheimer's disease (AD) and Down syndrome (DS) share a common therapeutic target, the dual-specificity, tyrosine phosphorylation activated kinase 1A (DYRK1A). Abnormally active DYRK1A is responsible for cognitive disorders (memory, learning, spatial localization) observed in both conditions. In DS, DYRK1A is overexpressed due to the presence of the DYRK1A gene on chromosome 21.
View Article and Find Full Text PDFSci Rep
October 2024
Institute of Pharmacology and Toxicology, RWTH Aachen University, Wendlingweg 2, 52074, Aachen, Germany.
The protein kinases DYRK1A and DYRK1B are pivotal regulators of cell cycle progression by promoting cell cycle exit into quiescence. DYRK1B appears to play a more important role in cancer cell quiescence than DYRK1A, as evidenced by its overexpression or copy number variations in human tumour samples. Nonetheless, the stimuli driving DYRK1B upregulation and the potential divergence in expression patterns between DYRK1A and DYRK1B remain largely elusive.
View Article and Find Full Text PDFFront Neurosci
September 2024
Department of Biology, Indiana University Indianapolis, Indianapolis, IN, United States.
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