Martinez-Valdez H, Cohen A
Division of Immunology/Rheumatology, Research Institute, Hospital for Sick Children, Toronto, ON, Canada.
Proc Natl Acad Sci U S A. 1988 Sep;85(18):6900-3. doi: 10.1073/pnas.85.18.6900.
Incubation of human thymocytes in the presence of phorbol esters caused a reversible decrease in the mRNAs encoding terminal deoxynucleotidyltransferase (TdT; EC 2.7.7.31) and adenosine deaminase (ADA; EC 3.5.4.4) and an increase in the mRNA encoding purine nucleoside phosphorylase (PNP; EC 2.4.2.1). The effect of phorbol esters on TdT and ADA mRNA levels can be attributed to an apparent decrease in the stability of the mRNAs. The changes in ADA, TdT, and PNP mRNAs closely simulate changes in the activities of these enzymes that occur during T-cell differentiation in vivo, suggesting a role for protein kinase C activation in the regulation of the expression of these genes during intrathymic T-cell differentiation. A role for these purine degradation enzymes in the regulation of intracellular pools of the deoxynucleotide substrates of TdT is discussed.
在佛波酯存在的情况下培养人胸腺细胞，会导致编码末端脱氧核苷酸转移酶（TdT；EC 2.7.7.31）和腺苷脱氨酶（ADA；EC 3.5.4.4）的mRNA可逆性减少，而编码嘌呤核苷磷酸化酶（PNP；EC 2.4.2.1）的mRNA增加。佛波酯对TdT和ADA mRNA水平的影响可归因于mRNA稳定性的明显降低。ADA、TdT和PNP mRNA的变化紧密模拟了体内T细胞分化过程中这些酶活性的变化，提示蛋白激酶C激活在胸腺内T细胞分化过程中这些基因表达的调控中起作用。还讨论了这些嘌呤降解酶在TdT脱氧核苷酸底物细胞内池调控中的作用。
