Presenilins regulate the cellular level of the tumor suppressor PTEN

Zhang, Han; Liu, Runzhong; Wang, Ruishan; Hong, Shuigen; Xu, Huaxi; Zhang, Yun-wu

doi:10.1016/j.neurobiolaging.2006.11.020

« Previous Next »Neurobiology of Aging
Volume 29, Issue 5 , Pages 653-660, May 2008

Presenilins regulate the cellular level of the tumor suppressor PTEN

Han Zhang
- Institute for Biomedical Research and School of Life Sciences, Xiamen University, 361005 Xiamen, China
- Both authors contributed equally to this work.
Runzhong Liu
- Institute for Biomedical Research and School of Life Sciences, Xiamen University, 361005 Xiamen, China
- Both authors contributed equally to this work.
Ruishan Wang
- Institute for Biomedical Research and School of Life Sciences, Xiamen University, 361005 Xiamen, China
Shuigen Hong
- Institute for Biomedical Research and School of Life Sciences, Xiamen University, 361005 Xiamen, China
Huaxi Xu
- Institute for Biomedical Research and School of Life Sciences, Xiamen University, 361005 Xiamen, China
- Burnham Institute for Medical Research, La Jolla, CA 92037, USA
- Corresponding authors at: Institute for Biomedical Research and School of Life Sciences, Xiamen University, 361005 Xiamen, China. Tel.: +86 592 2188568; fax: +86 592 2188528.
Yun-wu Zhang
- Institute for Biomedical Research and School of Life Sciences, Xiamen University, 361005 Xiamen, China
- Burnham Institute for Medical Research, La Jolla, CA 92037, USA
- Corresponding authors at: Institute for Biomedical Research and School of Life Sciences, Xiamen University, 361005 Xiamen, China. Tel.: +86 592 2188568; fax: +86 592 2188528.

Received 14 October 2006; received in revised form 17 November 2006; accepted 28 November 2006. published online 15 January 2007.

Abstract

Alzheimer's Disease (AD) is characterized by amyloid plaques consisting of β-amyloid (Aβ) peptides and neurofibrillary tangles consisting of hyperphosphorylated tau protein. Aβ is proteolytically derived from its precursor protein through cleavages by β-secretase and γ-secretase complex comprising presenilins (PS, PS1/PS2), nicastrin, APH-1 and PEN-2. PS1 is also known to activate the PI3K/Akt cell survival pathway in a γ-secretase-independent manner. The tumor suppressor PTEN, which antagonizes the PI3K/Akt pathway, has increasingly been recognized to play a key role in neural functions and its level found reduced in AD brains. Here, we demonstrate that the protein level of PTEN is dramatically reduced in cultured cells and embryonic tissues deficient in PS, and in the cortical neurons of PS1/PS2 conditional double knockout mice. Restoration of PS in PS-deficient cells reverses the reduction of PTEN. Regulation of PTEN by PS is independent of the PS/γ-secretase activity since impaired γ-secretase by the γ-secretase inhibitor treatment or due to nicastrin deficiency has little effect on the protein level of PTEN. Our data suggest an important role for PS in signaling pathways involving PI3K/Akt and PTEN that are crucial for physiological functions and the pathogenesis of multiple diseases.

Keywords: Akt, Alzheimer's Disease, Phosphatase and tensin homologue deleted on chromosome 10, Phosphoinositide 3-kinase, Presenilin