Inhibition of proliferation of primary avian fibroblasts through expression of histone H5 depends on the degree of phosphorylation of the protein.
Inhibition of proliferation of primary avian fibroblasts through expression of histone H5 depends on the degree of phosphorylation of the protein.
复制标题
DOI：
10.1083/jcb.113.3.497
复制
发表时间：
1991-05
期刊：
影响因子：
--
通讯作者：
Mura CV
中科院分区：
文献类型：
--
作者：
Aubert D;Garcia M;Benchaibi M;Poncet D;Chebloune Y;Verdier G;Nigon V;Samarut J;Mura CV
为了获得组蛋白H5的稳定和组成型表达，其水平与在正常鸡红细胞中观察到的水平相当，使用禽类自失活逆转录病毒载体将H5基因转移到不表达该蛋白的细胞中。通过去除禽白血病病毒RAV-2的3 'LTR的CAAT和TATA盒并插入H5序列获得载体pDAH 5。用重组病毒（DAH 5）感染QT 6鹌鹑细胞导致外源H5基因以低拷贝数稳定整合，形成正确起始的mRNA转录物并产生H5蛋白。表达的H5的量相当于成熟鸡红细胞的量。组蛋白H5在DAH 5转化细胞中的表达，如QT 6或AEV-ES 4转化的鸡胚成纤维细胞，对生长速率只有轻微的影响，并且不抑制细胞复制。相反，H5表达对正常鹌鹑和鸡成纤维细胞的影响是戏剧性的：细胞获得了静止成纤维细胞的外观，生长非常缓慢，细胞核看起来紧凑，经常从细胞中挤出。在QT 6转化细胞中产生的H5组蛋白被发现被磷酸化，而在正常的鸡成纤维细胞中，该蛋白缺乏这种翻译后修饰。有人提出，组蛋白H5的染色质凝聚作用被其磷酸化抑制。
To obtain stable and constitutive expression of histone H5 at levels comparable to those observed in normal chicken erythrocytes, an avian self-inactivating retroviral vector was used to transfer the H5 gene into cells which do not express this protein. The vector, pDAH5, was obtained by removing the CAAT and TATA boxes of the 3'LTR of the avian leukosis virus RAV-2 and inserting the H5 sequence. Infection of QT6 quail cells with the recombinant virus (DAH5) led to the stable integration of the foreign H5 gene at low copy number, to the formation of correctly initiated mRNA transcripts and to the production of H5 protein. The amount of H5 expressed was equivalent to that of a mature chicken erythrocyte. Expression of histone H5 in DAH5 transformed cells, such as QT6 or AEV-ES4, transformed chicken embryo fibroblasts had only slight effects on the growth rate and did not inhibit cell replication. Conversely, the effect of H5 expression on normal quail and chicken fibroblasts was dramatic: cells acquired the aspect of quiescent fibroblasts, grew very slowly, and nuclei looked compacted, often extruded from the cell. The H5 histone produced in QT6- transformed cells was found to be phosphorylated while in normal chicken fibroblasts the protein lacked this posttranslational modification. It is proposed that the chromatin-condensing role of histone H5 is inhibited by its phosphorylation.