Okada S, Ohba H, Taniyama M
J Inorg Biochem. 1981 Nov;15(3):223-31. doi: 10.1016/s0162-0134(00)80157-9.
The effect of Cr(III) on in vitro RNA synthesis directed by DNA and chromatin isolated from mouse liver was investigated in comparison with other inorganic metals. At 1 mM, CrCl3 significantly stimulated RNA synthesis when incubated with DNA or chromatin prior to the addition of Escherichia coli RNA polymerase, while other metals inhibited it. This stimulation by Cr(III) was caused even at 1 muM CrCl3 on either DNA- or chromatin- directed RNA synthesis. The Cr(III)-complexes of DNA and chromatin also showed significantly enhanced template activities. On the other hand, when RNA polymerase was preincubated with Cr(III), a remarkable inhibition was observed in RNA synthesis directed by both DNA and chromatin. In isolated mouse liver nuclei with endogenous RNA polymerases, Cr(III) stimulated Mg2+-activated RNA synthesis but not Mn2r-(NH4)2SO4-activated synthesis. These results suggest that Cr(III) may alter or regulate gene expressions in mammals.
与其他无机金属相比，研究了三价铬（Cr(III)）对从小鼠肝脏分离的DNA和染色质所指导的体外RNA合成的影响。在1 mM时，当在添加大肠杆菌RNA聚合酶之前将氯化铬（CrCl3）与DNA或染色质一起孵育时，它能显著刺激RNA合成，而其他金属则抑制RNA合成。即使在1 μM氯化铬（CrCl3）时，三价铬（Cr(III)）也能对DNA或染色质指导的RNA合成产生这种刺激作用。DNA和染色质的三价铬（Cr(III)）复合物也显示出模板活性显著增强。另一方面，当RNA聚合酶与三价铬（Cr(III)）预孵育时，在DNA和染色质所指导的RNA合成中均观察到明显的抑制作用。在具有内源性RNA聚合酶的分离小鼠肝细胞核中，三价铬（Cr(III)）刺激镁离子激活的RNA合成，但不刺激锰离子-硫酸铵激活的合成。这些结果表明，三价铬（Cr(III)）可能会改变或调节哺乳动物中的基因表达。
