University of Tasmania
Browse

File(s) not publicly available

PTEN is recruited to specific microdomains of the plasma membrane during lactacystin-induced neuronal apoptosis

journal contribution
posted on 2023-05-17, 01:43 authored by Choy, MS, Bay, BH, Cheng, HC, Cheung, NS
The tumor suppressor PTEN (phosphatase and tensin homolog deleted from chromosome 10) is a novel phosphatase displaying both protein and lipid phosphatase activities. In the central nervous system, PTEN plays an important role in the regulation of cell growth, differentiation and death. The tumor suppressor function of PTEN is attributed to its phospholipid phosphatase activity that dephosphorylates the plasma membrane phosphatidylinositol-(3,4,5)-triphosphate (PtdIns(3,4,5)P3). Since PTEN is normally localized in the cytosol, it needs to be targeted to the plasma membrane to dephosphorylate PtdIns(3,4,5)P3. We previously demonstrated that lactacystin-induced apoptosis of culture cortical neuron is associated with: (i) cleavage of PTEN (55 kDa) to a 50 kDa truncated form and (ii) accumulation of PTEN and all the truncated PTEN in a detergent-insoluble membrane fraction of the neuronal cells. Herein we demonstrate that a caspase-3 inhibitor suppresses cleavage of PTEN to the 50 kDa truncated form in culture cortical neurons in response to lactacystin treatment. Using immunogold transmission electron microscopy, we examined the distribution of PTEN in plasma membrane sheets stripped from cultured cortical neurons with and without treatment of lactacystin. Our results demonstrate that lactacystin treatment induces accumulation of PTEN to the inner surface of the plasma membrane sheets of the neuronal cells. Taken together, our data suggest that caspase-3-like proteases are involved in the conversion of PTEN to a 50-kDa truncated form and that PTEN and its truncated form accumulate at specific microdomains of the plasma membrane in neuronal cells undergoing apoptosis.

History

Publication title

Neuroscience Letters: An International Multidisciplinary Journal Devoted to The Rapid Publication of Basic Research in Neurosciences

Volume

405

Issue

1-2

Pagination

120-125

ISSN

0304-3940

Department/School

Menzies Institute for Medical Research

Publisher

Elsevier Sci Ireland Ltd

Place of publication

Customer Relations Manager, Bay 15, Shannon Industrial Estate Co, Clare, Ireland

Repository Status

  • Restricted

Socio-economic Objectives

Clinical health not elsewhere classified

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC