[PDF][PDF] The CD28 and CTLA-4 receptors associate with the serine/threonine phosphatase PP2A
E Chuang, TS Fisher, RW Morgan, MD Robbins… - Immunity, 2000 - cell.com
E Chuang, TS Fisher, RW Morgan, MD Robbins, JM Duerr, MG Vander Heiden, JP Gardner…
Immunity, 2000•cell.comCD28 and CTLA-4 are related members of a family of T lymphocyte cell surface receptors
that function to regulate T cell activation. We have found that the cytoplasmic domains of
both CTLA-4 and CD28 can associate with members of the PP2A family of serine/threonine
phosphatases. The association of PP2A with CD28 was negatively regulated by tyrosine
phosphorylation of the CD28 cytoplasmic domain. Inhibition of PP2A activity in Jurkat
leukemia T cells by treatment with okadaic acid or by expression of a dominant-negative …
that function to regulate T cell activation. We have found that the cytoplasmic domains of
both CTLA-4 and CD28 can associate with members of the PP2A family of serine/threonine
phosphatases. The association of PP2A with CD28 was negatively regulated by tyrosine
phosphorylation of the CD28 cytoplasmic domain. Inhibition of PP2A activity in Jurkat
leukemia T cells by treatment with okadaic acid or by expression of a dominant-negative …
Abstract
CD28 and CTLA-4 are related members of a family of T lymphocyte cell surface receptors that function to regulate T cell activation. We have found that the cytoplasmic domains of both CTLA-4 and CD28 can associate with members of the PP2A family of serine/threonine phosphatases. The association of PP2A with CD28 was negatively regulated by tyrosine phosphorylation of the CD28 cytoplasmic domain. Inhibition of PP2A activity in Jurkat leukemia T cells by treatment with okadaic acid or by expression of a dominant-negative mutant enhanced T cell activation induced by CD28 engagement. Interactions between cell surface receptors such as CTLA-4 and CD28 and serine/threonine phosphatases may represent a novel mechanism for modulating the intracellular signal transduction pathways associated with cell activation.
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