Peptide analogs of thymopentin distinguish distinct thymopoietin receptor specificities on two human T cell lines.
Thymopoietin, a polypeptide hormone of the thymus, and the synthetic pentapeptide thymopentin, corresponding to thymopoietin32-36, both induced elevations of intracellular cyclic GMP in two human T cell lines, CEM and MOLT-4. In contrast, the closely related polypeptide thysplenin, which differs from thymopoietin at position 34, induced intracellular cyclic GMP elevation in MOLT-4 but not in CEM. We synthesized a series of penta- and tetrapeptide analogs of amino acids 32-36 of human thymopoietin and thysplenin, and now show that distinct patterns of activity can be obtained in these small peptides, with selectivity for cyclic GMP elevation in MOLT-4 alone or CEM alone. This suggests that the thymopoietin receptors (TPR) on these two human T cell lines are distinguishable by their differing ligand specificities, and we have termed them alpha TPR and beta TPR for CEM and MOLT-4 receptors, respectively.
Heavner
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GA
Immunobiology Research Institute, Annandale, NJ 08801-0999.
Audhya
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T
Goldstein
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G
D002460:Cell Line; D006150:Guanine Nucleotides / Q000378:metabolism*; D006157:Guanosine Monophosphate / Q000378:metabolism*; D006801:Humans; D010446:Peptide Fragments / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism; D016305:Thymopentin; D013946:Thymopoietins / Q000378:metabolism*; D013951:Thymus Hormones / Q000378:metabolism*
D006150:Guanine Nucleotides; D010446:Peptide Fragments; D013946:Thymopoietins; D013951:Thymus Hormones; C032841:thymopoietin III; D006157:Guanosine Monophosphate; D016305:Thymopentin