非组蛋白染色体蛋白质：它们在组蛋白基因表达调控中的作用。

Non-histone chromosomal proteins: their role in the regulation of histone-gene expression.

作者信息

Stein G S, Stein J L, Kleinsmith L J, Jansing R L, Park W D, Thomson J A

出版信息

Biochem Soc Symp. 1977(42):137-63.

Abstract

Histone-gene expression was studied during the cell cycle of continuously dividing HeLa S3 cells and after stimulation of confluent monolayers of WI-38 human diploid fibroblasts to proliferate. The presence of histone-mRNA sequences was assayed by hybridization to a 3H-labelled single-stranded DNA complementary to histone-mRNA molecules. In HeLa S3 cells histone mRNA sequences were found in the nucleus and associated with polyribosomes during S-phase, but not during G1-phase. Transcripts of S-phase chromatin contained histone-mRNA sequences, but those of G1-phase chromatin did not. Similarly, in WI-38 cells association of histone-mRNA sequences with polyribosomes and transcription of histone-mRNA sequences from chromatin parallel DNA replication. Taken together these results suggest that the regulation of histone-gene expression resides, at least in part, at the transcriptional level. Chromatin-reconstitution studies provide evidence that non-histone chromosomal proteins play a key role in activation of histone-gene transcription during the period of the cell cycle when DNA is replicated. Phosphate groups associated with the S-phase non-histone chromosomal proteins appear to be functionally involved in the control of histone-gene readout.

摘要

在持续分裂的海拉S3细胞的细胞周期中以及在刺激汇合的WI-38人二倍体成纤维细胞单层使其增殖后，对组蛋白基因表达进行了研究。通过与与组蛋白mRNA分子互补的3H标记单链DNA杂交来检测组蛋白mRNA序列的存在。在海拉S3细胞中，在S期核中发现组蛋白mRNA序列并与多核糖体相关联，但在G1期则不然。S期染色质的转录本含有组蛋白mRNA序列，而G1期染色质的转录本则没有。同样，在WI-38细胞中，组蛋白mRNA序列与多核糖体的关联以及来自染色质的组蛋白mRNA序列的转录与DNA复制平行。这些结果综合起来表明，组蛋白基因表达的调控至少部分存在于转录水平。染色质重建研究提供了证据，表明非组蛋白染色体蛋白在细胞周期中DNA复制期间组蛋白基因转录的激活中起关键作用。与S期非组蛋白染色体蛋白相关的磷酸基团似乎在功能上参与了组蛋白基因读出的控制。