Open Access

Mislocalization of CDK11/PITSLRE, a regulator of the G2/M phase of the cell cycle, in Alzheimer disease

  • Vladan P. Bajić1Email author,
  • Bo Su2,
  • Hyoung-Gon Lee2,
  • Wataru Kudo2,
  • Sandra L. Siedlak2,
  • Lada Živković3,
  • Biljana Spremo-Potparević3,
  • Ninoslav Djelic4,
  • Zorana Milicevic5,
  • Avneet K. Singh2,
  • Lara M. Fahmy2,
  • Xinglong Wang2,
  • Mark A. Smith2 and
  • Xiongwei Zhu2Email author
Cellular & Molecular Biology LettersAn International Journal201116:11

DOI: 10.2478/s11658-011-0011-2

Received: 1 September 2010

Accepted: 28 March 2011

Published: 3 April 2011

Abstract

Post-mitotic neurons are typically terminally differentiated and in a quiescent status. However, in Alzheimer disease (AD), many neurons display ectopic re-expression of cell cycle-related proteins. Cyclin-dependent kinase 11 (CDK11) mRNA produces a 110-kDa protein (CDK11p110) throughout the cell cycle, a 58-kDa protein (CDK11p58) that is specifically translated from an internal ribosome entry site and expressed only in the G2/M phase of the cell cycle, and a 46-kDa protein (CDK11p46) that is considered to be apoptosis specific. CDK11 is required for sister chromatid cohesion and the completion of mitosis. In this study, we found that the expression patterns of CDK11 vary such that cytoplasmic CDK11 is increased in AD cellular processes, compared to a pronounced nuclear expression pattern in most controls. We also investigated the effect of amyloid precursor protein (APP) on CDK11 expression in vitro by using M17 cells overexpressing wild-type APP and APP Swedish mutant phenotype and found increased CDK11 expression compared to empty vector. In addition, amyloid-β25–35 resulted in increased CDK11 in M17 cells. These data suggest that CDK11 may play a vital role in cell cycle re-entry in AD neurons in an APP-dependent manner, thus presenting an intriguing novel function of the APP signaling pathway in AD.

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