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Prostaglandin E 1 activates a chloride current in Jurkat T lymphocytes via cAMP‐dependent protein kinase
Author(s) -
Maldonado D.,
Schumann M.,
Nghiem P.,
Dong Y.,
Gardner P.
Publication year - 1991
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.5.14.1721593
Subject(s) - jurkat cells , intracellular , protein kinase a , chloride channel , patch clamp , reversal potential , chemistry , biophysics , prostaglandin e1 , microbiology and biotechnology , kinase , endocrinology , biochemistry , biology , t cell , receptor , immunology , immune system
Patch‐clamp studies have identified a cAMP‐dependent Cl – conductance in lymphocytes that is defectively regulated in cystic fibrosis. In this study we used 125 I efflux and whole‐cell patch‐clamp studies to investigate whether prostaglandin E 1 (PGE 1 ), an agonist that generates intracellular cAMP in Jurkat T lymphocytes, activates a Cl – conductance. Stimulation of T cells by externally applied PGE 1 stimulated 125 I efflux and activated a slowly developing membrane current. When external and internal Cl – were about equal, the current reversed at about zero mV, but when external Cl – was lowered from 157 to 7 m m the reversal potential shifted 75 mV in the positive direction, demonstrating that the current carrier was Cl – . In addition, the current was blocked by 10 μ m 5‐nitro‐2(3‐phenylpropylamino) benzoic acid (NPPB), a potent Cl – channel blocker. A membrane‐permeable cAMP analog mimicked the effect of PGE 1 , whereas intracellular application of a cAMP antagonist Rp‐cAMP blocked the effect of PGE 1 . Addition of purified catalytic subunit of cAMP‐dependent protein kinase (PKA) plus ATP to the recording pipette also activated a similar current, whereas internally applied Walsh inhibitor, the synthetic peptide inhibitor of PKA, blocked the PGE 1 effect. These results suggest that PGE 1 , acting through PKA, activates a Cl – current in Jurkat T cells.—Maldonado, D.; Schumann, M.; Nghiem, P.; Dong, Y.; Gardner, P. Prostaglandin E 1 activates a chloride current in Jurkat T lymphocytes via cAMP‐dependent protein kinase. FASEB J. 5: 2965‐2970; 1991.