Subcellular localization of intracellular protein tyrosine phosphatases in T cells

Eur J Immunol. 2000 Aug;30(8):2412-21. doi: 10.1002/1521-4141(2000)30:8<2412::AID-IMMU2412>3.0.CO;2-J.

Abstract

A high protein tyrosine phosphatase (PTPase) activity is required to maintain circulating T lymphocytes in a resting phenotype, and to limit the initiation of T cell activation. We report that 15 of the currently known 24 intracellular PTPases are expressed in T cells, namely HePTP, TCPTP, SHP1, SHP2, PEP, PTP-PEST, PTP-MEG2, PTEN, PTPH1, PTP-MEG1, PTP36, PTP-BAS, LMPTP, PRL-1 and OV-1. Most were found in the cytosol and many were enriched at the plasma membrane. Only TCPTP and PTP-MEG2 had subcellular localizations that essentially excludes them from a direct role in early T cell antigen receptor signaling events. Overexpression of 6 of the PTPases reduced IL-2 gene activation, 3 of them thereby identified as novel candidates for negative regulators of TCR signaling. Our findings expand the repertoire of PTPases that should be considered for a regulatory role in T cell activation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Membrane / enzymology
  • Cell Nucleus / enzymology
  • Cytoplasm / enzymology
  • Cytoskeleton / enzymology
  • Endoplasmic Reticulum / enzymology
  • Hematopoietic System / enzymology
  • Humans
  • Jurkat Cells
  • Lymphocyte Activation
  • Lymphoid Tissue / enzymology
  • Protein Tyrosine Phosphatases / analysis*
  • T-Lymphocytes / enzymology*
  • T-Lymphocytes / ultrastructure

Substances

  • Protein Tyrosine Phosphatases