Structure, chromosome location, and expression of the human gamma-actin gene: differential evolution, location, and expression of the cytoskeletal beta- and gamma-actin genes
Structure, chromosome location, and expression of the human gamma-actin gene: differential evolution, location, and expression of the cytoskeletal beta- and gamma-actin genes
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DOI：
10.1128/mcb.8.4.1775-1789.1988
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发表时间：
1988-04
影响因子：
5.3
通讯作者：
H. Erba;R. Eddy;T. Shows;L. Kedes;P. Gunning
中科院分区：
文献类型：
--
作者：
H. Erba;R. Eddy;T. Shows;L. Kedes;P. Gunning
细胞骨架β -和γ -肌动蛋白mrna的积累在多种小鼠组织和器官中被确定。β -异构体总是比γ -异构体多表达。然而，β -与-肌动蛋白mRNA的摩尔比在肾脏和睾丸中为1.7，在肌肉组织中为12，在肝脏中为114。我们得出结论，尽管细胞骨架β -和γ -肌动素确实是共表达的，但它们的mRNA水平在不同细胞类型之间受到不同的调节。人类γ -肌动蛋白基因已被克隆并测序，其染色体位置已被确定。该基因位于人类第17号染色体上，不像-肌动蛋白位于第7号染色体上。因此，如果这些基因在小鼠中也未连接，则不能通过基因连接来确定-和-肌动蛋白基因在啮齿动物组织中的共表达。人类β -肌动蛋白和γ -肌动蛋白基因的比较表明，自复制产生这两个基因以来，5'侧区和内含子III的非编码序列一直是保守的。相比之下，在-肌动蛋白基因中不存在的内含子III和3'-未翻译区有一些序列，但在人类-肌动蛋白和北方爪蟾1型肌动蛋白基因之间是保守的。这些保守的非编码序列可能与-和-肌动蛋白的共表达有关，也可能与-肌动蛋白基因的独特调控和功能有关。最后，我们证明了人γ -肌动蛋白基因在导入小鼠L细胞和C2成肌细胞后表达，并且在C2细胞融合形成肌管后，人γ -肌动蛋白基因被适当调节。
The accumulation of the cytoskeletal beta- and gamma-actin mRNAs was determined in a variety of mouse tissues and organs. The beta-isoform is always expressed in excess of the gamma-isoform. However, the molar ratio of beta- to gamma-actin mRNA varies from 1.7 in kidney and testis to 12 in sarcomeric muscle to 114 in liver. We conclude that, whereas the cytoskeletal beta- and gamma-actins are truly coexpressed, their mRNA levels are subject to differential regulation between different cell types. The human gamma-actin gene has been cloned and sequenced, and its chromosome location has been determined. The gene is located on human chromosome 17, unlike beta-actin which is on chromosome 7. Thus, if these genes are also unlinked in the mouse, the coexpression of the beta- and gamma-actin genes in rodent tissues cannot be determined by gene linkage. Comparison of the human beta- and gamma-actin genes reveals that noncoding sequences in the 5'-flanking region and in intron III have been conserved since the duplication that gave rise to these two genes. In contrast, there are sequences in intron III and the 3'-untranslated region which are not present in the beta-actin gene but are conserved between the human gamma-actin and the Xenopus borealis type 1 actin genes. Such conserved noncoding sequences may contribute to the coexpression of beta- and gamma-actin or to the unique regulation and function of the gamma-actin gene. Finally, we demonstrate that the human gamma-actin gene is expressed after introduction into mouse L cells and C2 myoblasts and that, upon fusion of C2 cells to form myotubes, the human gamma-actin gene is appropriately regulated.