Parra, Eduardo and Hecht, Pedro (2021) Leukemia T Cells as a Model to Study the Activity of the Phosphatase PP4 in the Regulation of T Cell Response. In: Recent Developments in Medicine and Medical Research Vol. 13. B P International, pp. 1-13. ISBN 978-93-5547-159-8
Full text not available from this repository.Abstract
Human leukemia cell lines are powerful tools for investigating basic and applied aspects of T cell biology. The leukemia cells mimic the normal activity of T cells, among other advantages, they offer worldwide availability of identical cell material, and they can be cryopreserved. The phosphatase PP4 is a PP2A-related, okadaic acid-sensitive, serine/threonine protein phosphatase that shares 65% amino acid identity with PP2A. Many studies have shown that protein phosphatase is involved in the regulation of T-cell signalling and activation. We have investigated the effect of over expression of PP4 in the expression of the member of the MAP kinase family in Jurkat leukemia T cells which have been previously stimulated with UV, TPA, Ionomycin and okadaic acid. We found that over expression of PP4 expressed relatively low activity in the absence of any kind of stimulation. However, TPA, UV or Ionomycin treatment strongly increases the activity of PP4. In addition, Jurkat T cells, transfected with various expression plasmids and/or stimulated with TPA, UV or Ionomycin strongly induces the c-Jun N-terminal kinase (JNK) and p38, whereas ERK-1/2 kinase pathway are weekly activated. Treatment of Jurkat T cells with okadaic acid, an inhibitor of PP2 phosphatase; also inhibit the increasing of JNK and p38 activity induced by PP4. The effect of okadaic acid in the activity of PP4 was similar to the observed in Jurkat T cells treated with a dominant negative for c-Jun (dn-jun). These results indicate that activation of JNK and p38 but not of ERKs is a target for the PP4 phosphatase activity in Jurkat leukemic T cells.
Item Type: | Book Section |
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Subjects: | GO for ARCHIVE > Medical Science |
Depositing User: | Unnamed user with email support@goforarchive.com |
Date Deposited: | 17 Oct 2023 05:33 |
Last Modified: | 17 Oct 2023 05:33 |
URI: | http://eprints.go4mailburst.com/id/eprint/1394 |