These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: PP2A-dependent control of transcriptionally active FOXO3a in CD8(+) central memory lymphocyte survival requires p47(phox).
    Author: Liu Q, Yi L, Sadiq-Ali S, Koontz SM, Wood A, Zhu N, Jackson SH.
    Journal: Cell Death Dis; 2012 Aug 23; 3(8):e375. PubMed ID: 22914323.
    Abstract:
    Forkhead box O3a (FOXO3a) transcription factor is regulated by complex post-translational modifications that allow for transcriptional control of various apoptosis factors including pro-apoptotic Bim. Although it has been shown that kinases phosphorylate FOXO3a in memory T cells, the role of protein phosphatases in the control of memory T lymphocyte FOXO3a function is less clear. Here, we report that FOXO3a is dephosphorylated (activated) by a protein phosphatase 2A (PP2A)-dependent mechanism in CD8(+) memory lymphocytes (Tm) during Listeria monocytogenes (Lm) infection, which allows for enhanced Bim transcription in nicotinamide adenine dinucleotide phosphate-oxidase p47(phox)-deficient (p47(phox-/-)) Tm. Consequently, CD8(+) Tm from Lm-infected p47(phox-/-) mice express significantly higher levels of each pro-apoptotic Bim protein isoform. Furthermore, there was a profound reduction in the accumulation of CD8(+) T central memory (Tcm) cells in infected p47(phox-/-) spleens, and 65% p47(phox-/-) mouse moribundity following secondary Lm reinfection compared with 25% in wild-type mice. Notably, blocking PP2A activity attenuated FOXO3 activation and Bim transcription in p47(phox-/-) CD8(+) memory lymphocytes. Our findings indicate a critical role for p47(phox) in a dynamic interplay between PP2A and FOXO3a that regulates pro-apoptotic Bim transcription in CD8(+) memory lymphocytes during infection.
    [Abstract] [Full Text] [Related] [New Search]