Kleinsmith L J, Stein J, Stein G
Proc Natl Acad Sci U S A. 1976 Apr;73(4):1174-8. doi: 10.1073/pnas.73.4.1174.
A nonhistone phosphatase devoid of detectable protease activity has been purified from nuclear sap by chromatography on DEAE-Sephadex. After linkage to an insoluble agarose matrix, this enzyme was used to dephosphorylate nonhistone proteins obtained from S-phase HeLa cells. Chromatin reconstituted with these dephosphorylated proteins exhibited roughly a 50% reduction in the overall number of initiation sites available for transcription when compared to controls. Specific measurements of transcription of histone genes with use of a complementary DNA probe showed that genes coding for histones are preferentially inhibited after nonhistone dephosphorylation. These results provide the first direct support for the theory that phosphorylation of nonhistone proteins is involved in regulating the availability of individual genes for transcription.
一种没有可检测到的蛋白酶活性的非组蛋白磷酸酶已通过在DEAE-葡聚糖凝胶上的色谱法从核液中纯化出来。与不溶性琼脂糖基质连接后，这种酶被用于使从S期海拉细胞获得的非组蛋白去磷酸化。与对照相比，用这些去磷酸化蛋白质重构的染色质在可用于转录的起始位点总数上大致减少了50%。使用互补DNA探针进行的组蛋白基因转录的特异性测量表明，在非组蛋白去磷酸化后，编码组蛋白的基因受到优先抑制。这些结果为非组蛋白蛋白质的磷酸化参与调节单个基因转录可用性的理论提供了首个直接支持。
