Harada S, Haneda E, Maekawa T, Morikawa Y, Funayama S, Nagata N, Ohtsuki K, Nagata N, Ohtsuki K
Laboratory of Genetical Biochemistry, School of Allied Health Sciences, Kitasato University, Sagamihara, Japan.
Biol Pharm Bull. 1999 Oct;22(10):1122-6. doi: 10.1248/bpb.22.1122.
The physiological significance of the casein kinase II (CK-II)-mediated phosphorylation of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) on its three enzymatic activities [RNA-dependent DNA polymerase (RDDP), DNA-dependent DNA polymerase (DDDP) and ribonuclease H (RNase H)] was investigated in vitro. It was found that (i) the purified recombinant RT (rRT) functioned as an effective phosphate acceptor for CK-II; (ii) the RDDP, DDDP and RNase H activity of rRT was stimulated about 2.8-, 4.1- and 3.9-fold, respectively, after full phosphorylation by CK-II; and (iii) this stimulation was selectively inhibited by potent CK-II inhibitors, such as neocarzinostatin-chromophore (NCS-chrom) and three polyphenol-containing anti-oxidant compounds [quercetin, epigallocatechin gallate (EGCG) and 8-chloro-3',4',5,7-tetrahydroxyisoflavone (8C-3',4',5,7-THI)]. These results suggest that (i) CK-II may be responsible for activation of RT in HIV-1-infected cells; and (ii) the selective inhibition of CK-II-mediated activation of HIV-1 RT by potent CK-II inhibitors may be involved in the mechanism of their anti-HIV-1 effects at the cellular level.
在体外研究了酪蛋白激酶II（CK-II）介导的人免疫缺陷病毒1型（HIV-1）逆转录酶（RT）的磷酸化对其三种酶活性[RNA依赖性DNA聚合酶（RDDP）、DNA依赖性DNA聚合酶（DDDP）和核糖核酸酶H（RNase H）]的生理意义。结果发现：（i）纯化的重组RT（rRT）可作为CK-II有效的磷酸受体；（ii）经CK-II完全磷酸化后，rRT的RDDP、DDDP和RNase H活性分别被刺激约2.8倍、4.1倍和3.9倍；（iii）这种刺激被有效的CK-II抑制剂选择性抑制，如新制癌菌素发色团（NCS-chrom）和三种含多酚的抗氧化化合物[槲皮素、表没食子儿茶素没食子酸酯（EGCG）和8-氯-3',4',5,7-四羟基异黄酮（8C-3',4',5,7-THI）]。这些结果表明：（i）CK-II可能负责HIV-1感染细胞中RT的激活；（ii）有效的CK-II抑制剂对CK-II介导的HIV-1 RT激活的选择性抑制可能参与了它们在细胞水平上的抗HIV-1作用机制。
