Avian serum response factor expression restricted primarily to muscle cell lineages is required for alpha-actin gene transcription
Avian serum response factor expression restricted primarily to muscle cell lineages is required for alpha-actin gene transcription
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DOI：
10.1006/dbio.1996.0160
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发表时间：
1996-07-10
影响因子：
2.7
通讯作者：
Schwartz, RJ
中科院分区：
文献类型：
--
作者：
Croissant, JD;Kim, JH;Schwartz, RJ
禽类胚胎肌肉谱系中的血清反应因子（SRF）基因表达在激活α-肌动蛋白基因活性中发挥着核心作用。在早期 HH 6 禽类胚胎中，SRF mRNA 表达强烈定位于神经沟、原条、侧板中胚层和 Hensen 结，而到 HH 8 阶段，在神经皱襞和体节中发现了明显的 SRF 表达。SRF 转录本出现在 HH 9 阶段胚胎的心前内脏中胚层中，并在心肌、体节和外侧中胚层中检测到更高水平HH 11 胚胎。 SRF 抗体染色表明，发育中的心脏的心肌和体节的肌节部分有显着的 SRF 蛋白积累。在培养物的初级成肌过程中，随着初级成肌细胞退出细胞周期，SRF 转录本和核 SRF 蛋白含量增加了约 40 倍，在骨骼 α-肌动蛋白基因上调之前达到最高水平。显性失活的 SRF 突变体 SRFpm1 抑制 DNA 结合，但不抑制单体 SRF 亚基的二聚化，在肌发生过程中阻断骨骼 α-肌动蛋白启动子-荧光素酶报告基因的转录激活。共转染野生型 SRF 表达载体可逆转转录阻断，但不能通过表达其他生肌因子（例如 MyoD 和 Mef-2C）来挽救。因此，SRF表现出主要限于横纹肌细胞谱系的胚胎表达模式，其中核SRF质量的增加是α-肌动蛋白基因转录所必需的。 (C) 1996 学术出版社
Serum response factor (SRF) gene expression in avian embryonic muscle lineages plays a central role in activating alpha-actin gene activity. In early stage HH 6 avian embryos, SRF mRNA expression showed strong localization to the neural groove, primitive streak, lateral plate mesoderm, and Hensen's node, while distinct SRF expression was seen later in the neural folds and the somites by HH stage 8. SRF transcripts appeared in the precardiac splanchnic mesoderm in stage HH 9 embryos and was detected at higher levels in the myocardium, somites, and lateral mesoderm of HH 11 embryos. SRF antibody staining demonstrated significant SRF protein accumulation in the myocardium of the developing heart and the myotomal portion of somites. During primary myogenesis in culture, SRF transcripts and nuclear SRF protein content increased about 40-fold, as primary myoblasts withdrew from the cell cycle, reaching their highest levels prior to the upregulation of the skeletal alpha-actin gene. A dominant-negative SRF mutant, SRFpm1, which inhibited DNA binding, but not dimerization of monomeric SRF subunits, blocked transcriptional activation of a skeletal alpha-actin promoter-luciferase reporter gene during myogenesis. Transcriptional blockade was reversed by co-transfections of a wild-type SRF expression vector, but was not rescued by the expression of other myogenic factors, such as MyoD and Mef-2C. Thus, SRF displayed an embryonic expression pattern restricted primarily to striated muscle cell lineages, in which increased mass of nuclear SRF was obligatory for alpha-actin gene transcription. (C) 1996 Academic Press, Inc.