A new cyclic nucleotide phosphodiesterase isozyme expressed in the T-lymphocyte cell lines.
Cytosolic phosphodiesterase activities of Jurkat, a human T-lymphocyte cell line, were resolved by high performance liquid chromatography into two major peaks of cAMP-specific enzyme. One was the Rolipram-sensitive isozyme. The other showed a low Km value (0.45 +/- 0.04 microM) for cAMP and different properties from reported isozymes in that it was hardly affected by well-known phosphodiesterase inhibitors or activators. This enzyme, "JK-21", was found in other human T-cell lines, MOLT-4, HPB-ALL and HUT-78, whereas no fraction containing JK-21 was detected in human B-lymphocyte cell lines, Jijoye, JY and Namalwa and in human promyelocytic cell line, HL-60. The results indicate that JK-21 is a new phosphodiesterase isozyme localized to T-cells.
Pharmaceutical Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., Shizuoka, Japan.
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D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases / Q000302:isolation & purification / Q000378:metabolism*; D001402:B-Lymphocytes / Q000201:enzymology; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology; D006801:Humans; D007700:Kinetics; D013379:Substrate Specificity; D013601:T-Lymphocytes / Q000201:enzymology*; D014407:Tumor Cells, Cultured
D000242:Cyclic AMP; D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases; D006152:Cyclic GMP