A HUMAN HISTONE H2B.1 VARIANT GENE, LOCATED ON CHROMOSOME-1, UTILIZES ALTERNATIVE-3' END PROCESSING
A HUMAN HISTONE H2B.1 VARIANT GENE, LOCATED ON CHROMOSOME-1, UTILIZES ALTERNATIVE-3' END PROCESSING
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DOI：
10.1002/jcb.240500406
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发表时间：
1992-12-01
影响因子：
4
通讯作者：
STEIN, GS
中科院分区：
文献类型：
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作者：
COLLART, D;ROMAIN, PL;STEIN, GS
人类H_2B组蛋白变异基因(GL105)已被克隆，该基因编码2300nT的非复制依赖的信使核糖核酸。我们证明了该基因表达在HeLa S3细胞周期中差异调节的可选的mRNAs。H_2B-GL105基因编码一个500个核苷酸的细胞周期依赖的mRNA和一个2300个核苷酸的组成性表达的mRNA。细胞周期调节的mRNA的3‘末端紧跟在大多数组蛋白mRNAs典型的连接的二联体对称区之后，而结构性表达的mRNA有一个1798个核苷酸的非翻译拖尾，它包含相同的连接的二联体对称性区域，但是多腺化的。H 2B-GL105 mRNAs的帽部位位于蛋白质编码区上游42nT。通过染色体原位杂交和利用H 2B-GL105特异性探针对啮齿动物-人类体细胞杂交进行分析，将H 2B-GL105组蛋白基因定位于染色体1q21-1q23区域。H_2B-GL105基因与一个具有功能的H_2A组蛋白基因配对，这对H_2A/H_2B基因由一个双向转录的基因间启动子区和一个OTF-1元件隔开。这些结果表明，细胞周期调控和结构性表达的组蛋白mRNAs可以由同一基因编码，提示交替的3‘端加工可能是组蛋白mRNAs调控的重要机制。这种控制进一步增加了细胞在细胞周期和分化开始时调节复制依赖的和变异组蛋白的合成的多功能性。
A variant human H2B histone gene (GL105), previously shown to encode a 2300 nt replication independent mRNA, has been cloned. We demonstrate this gene expresses alternative mRNAs regulated differentially during the HeLa S3 cell cycle. The H2B-GL105 gene encodes both a 500 nt cell cycle dependent mRNA and a 2300 nt constitutively expressed mRNA. The 3' end of the cell cycle regulated mRNA terminates immediately following the region of hyphenated dyad symmetry typical of most histone mRNAs, whereas the constitutively expressed mRNA has a 1798 nt non-translated trailer that contains the same region of hyphenated dyad symmetry but is polyadenylated. The cap site for the H2B-GL105 mRNAs is located 42 nt upstream of the protein coding region. The H2B-GL105 histone gene was localized to chromosome region 1q21-1q23 by chromosomal in situ hybridization and by analysis of rodent-human somatic cell hybrids using an H2B-GL105 specific probe. The H2B-GL105 gene is paired with a functional H2A histone gene and this H2A/H2B gene pair is separated by a bidirectionally transcribed intergenic promoter region containing consensus TATA and CCAAT boxes and an OTF-1 element. These results demonstrate that cell cycle regulated and constitutively expressed histone mRNAs can be encoded by the same gene, and indicate that alternative 3' end processing may be an important mechanism for regulation of histone mRNA. Such control further increases the versatility by which cells can modulate the synthesis of replication-dependent as well as variant histone proteins during the cell cycle and at the onset of differentiation.