Sun J M, Ali Z, Lurz R, Ruiz-Carrillo A
Cancer Research Center, Laval University School of Medicine, L'Hotel-Dieu de Québec, Canada.
EMBO J. 1990 May;9(5):1651-8. doi: 10.1002/j.1460-2075.1990.tb08285.x.
In vivo competition between histones H1 and H5 for chromatin has been studied in rat sarcoma XC10 cells transfected with a glucocorticoid responsive MMTV-H5 gene. Activation of H5 expression results in accumulation of H5 in the nuclei where it partially replaces H1. H5 displaces H1 from its primary binding sites presumably during chromatin replication and also binds with high affinity to secondary chromatin sites normally not occupied by H1. Replacement of H1 by H5 to levels similar to those of mature chicken erythrocytes does not alter the nucleosome repeat length of chromatin. This indicates that H5 is not solely responsible for the increase in nucleosome spacing of maturing erythroid cells. Exchange of H1 by H5 in vivo or in vitro results in a higher compaction/stability of chromatin.
在转染了糖皮质激素反应性MMTV - H5基因的大鼠肉瘤XC10细胞中，研究了组蛋白H1和H5在染色质上的体内竞争。H5表达的激活导致H5在细胞核中积累，在那里它部分取代了H1。H5可能在染色质复制过程中从其主要结合位点取代H1，并且还以高亲和力与通常未被H1占据的二级染色质位点结合。将H1替换为与成熟鸡红细胞相似水平的H5，不会改变染色质的核小体重复长度。这表明H5并非成熟红细胞核小体间距增加的唯一原因。在体内或体外将H1替换为H5会导致染色质更高的压缩/稳定性。
