Sakagami H, Mitsui Y, Murota S, Yamada M
J Cell Physiol. 1982 Feb;110(2):213-8. doi: 10.1002/jcp.1041100216.
Metabolism of histone H1 at different stages of cell growth was investigated in order to get a better understanding of the role of histone H1 in the cell growth of human diploid fibroblasts. Histone H1 content exhibited some fluctuation during the culture stage of cell growth. When cells entered confluent phase, the ratio of histone H1 to total histones decreased significantly. Histone H1 had a turnover half-life of 80 hours whereas nucleosomal histones did not significantly turn-over regardless of the growth stage. DNA synthesis was drastically diminished with increased cell density whereas histone synthesis was less sensitive to contact-inhibition. The gradual decline of histone H1 content with increased cell density suggests that its degradation is slightly superior to its residual synthesis. When the confluent cells were seeded at low density, cell proliferation resumed and histone H1 was synthesized and deposited to chromatin in a greater amount than nucleosomal histones, thus resulting in an abrupt increase of histone H1 content. The possible role of histone H1 metabolism in normal cells is discussed.
为了更好地理解组蛋白H1在人二倍体成纤维细胞生长中的作用，对细胞生长不同阶段的组蛋白H1代谢进行了研究。在细胞生长的培养阶段，组蛋白H1含量呈现出一些波动。当细胞进入汇合期时，组蛋白H1与总组蛋白的比例显著下降。组蛋白H1的周转半衰期为80小时，而核小体组蛋白无论生长阶段如何都没有明显的周转。随着细胞密度增加，DNA合成急剧减少，而组蛋白合成对接触抑制不太敏感。随着细胞密度增加，组蛋白H1含量逐渐下降，这表明其降解略优于残余合成。当汇合细胞以低密度接种时，细胞增殖恢复，组蛋白H1被合成并以比核小体组蛋白更多的量沉积到染色质中，从而导致组蛋白H1含量突然增加。讨论了组蛋白H1代谢在正常细胞中的可能作用。
