Dual-specificity tyrosine(Y)-phosphorylation regulated kinase 1A-mediated phosphorylation of amyloid precursor protein: evidence for a functional link between Down syndrome and Alzheimer's disease

J Neurochem. 2008 Mar;104(5):1333-44. doi: 10.1111/j.1471-4159.2007.05075.x. Epub 2007 Nov 14.


Most individuals with Down Syndrome (DS) show an early-onset of Alzheimer's disease (AD), which potentially results from the presence of an extra copy of a segment of chromosome 21. Located on chromosome 21 are the genes that encode beta-amyloid (Abeta) precursor protein (APP ), a key protein involved in the pathogenesis of AD, and dual-specificity tyrosine(Y)-phosphorylation regulated kinase 1A (DYRK1A ), a proline-directed protein kinase that plays a critical role in neurodevelopment. Here, we describe a potential mechanism for the regulation of AD pathology in DS brains by DYRK1A-mediated phosphorylation of APP. We show that APP is phosphorylated at Thr668 by DYRK1A in vitro and in mammalian cells. The amounts of phospho-APP and Abeta are increased in the brains of transgenic mice that over-express the human DYRK1A protein. Furthermore, we show that the amounts of phospho-APP as well as those of APP and DYRK1A are elevated in human DS brains. Taken together, these results reveal a potential regulatory link between APP and DYRK1A in DS brains, and suggest that the over-expression of DYRK1A in DS may play a role in accelerating AD pathogenesis through phosphorylation of APP.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / genetics
  • Alzheimer Disease / metabolism*
  • Amyloid beta-Protein Precursor / genetics
  • Amyloid beta-Protein Precursor / metabolism*
  • Animals
  • Cell Line
  • Down Syndrome / genetics
  • Down Syndrome / metabolism*
  • Gene Expression Regulation / physiology
  • Humans
  • Mice
  • Mice, Transgenic
  • PC12 Cells
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / isolation & purification
  • Protein-Serine-Threonine Kinases / physiology*
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / isolation & purification
  • Protein-Tyrosine Kinases / physiology*
  • Rats
  • Threonine / metabolism
  • Tyrosine / metabolism*


  • Amyloid beta-Protein Precursor
  • Threonine
  • Tyrosine
  • Dyrk kinase
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases