Gene Expression At Beginning Of Mammalian Development

哺乳动物发育初期的基因表达

• 批准号: 7201708
• 负责人: Melvin DePamphilis
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7201708
• 关键词: CpG islands; DNA methylation; DNA replication; RNA binding protein; acrosome; cell differentiation; cell line; developmental genetics; early embryonic stage; embryonic stem cell; genetic regulatory element; immunoprecipitation; laboratory mouse; mammalian embryology; nucleolus; phosphorylation; protein localization; protein protein interaction; protein quantitation /detection; transcription factor; CpG islands; DNA methylation; DNA replication; RNA binding protein; acrosome; cell differentiation; cell line; developmental genetics; early embryonic stage; embryonic stem cell; genetic regulatory element; immunoprecipitation; laboratory mouse; mammalian embryology; nucleolus; phosphorylation; protein localization; protein protein interaction; protein quantitation /detection; transcription factor

Kohn, M.J., K.J. Kaneko and M.L. DePamphilis (2005) DkkL1(Soggy), A Dickkopf Family Member, Localizes To The Acrosome During Mammalian Spermatogenesis, Mol. Reprod. Dev. 71:516-522. Dickkopf-like 1 (DkkL1) is related to the Dickkopf gene family, a group of proteins that are characterized as secreted antagonists of Wingless signal transduction proteins. DkkL1 mRNA is found in preimplantation mouse embryos and in developing neural tissue, but in adults it is found primarily in the testes. In an effort to elucidate its function, the distribution of Dickkopf-like 1 protein (DkkL1) in mouse testis and mature sperm was analyzed by immuno-histochemistry and immuno-blotting techniques. DkkL1 first appeared in the developing spermatocytes in seminiferous tubules as early as Stage XII, coincident with the appearance of DkkL1 mRNA. Surprisingly, however, DkkL1 localized to the developing acrosome in spermatocytes and spermatids and to the acrosome in mature sperm. Furthermore, DkkL1 was N-glycosylated in the testis, but it did not appear to be excreted, and the DkkL1 in mature sperm was no longer N-glycosylated, suggesting that additional post-translational modifications occurred during the final stages of spermatogenesis. These results identify a member of the Dickkopf family as a novel acrosomal protein that may be involved in acrosome assembly or function, a unique role for a secreted signaling molecule. Kaneko, K.J., T. Rein, Z-S Guo, K. Latham and M.L. DePamphilis. (2004) DNA Methylation May Restrict But Does Not Determine Differential Gene Expression at the Sgy/Tead2 locus During Mouse Development, Mol. Cell. Biol. 24:1968-1982. Soggy (Sgy) and Tead2, two closely linked genes with CpG islands, were coordinately expressed in mouse preimplantation embryos and embryonic stem (ES) cells, but were differentially expressed in differentiated cells. Analysis of established cell lines revealed that Sgy gene expression could be fully repressed by methylation of the Sgy promoter, and that DNA methylation acted synergistically with chromatin deacetylation. Differential gene expression correlated with differential DNA methylation, resulting in sharp transitions from methylated to unmethylated DNA at the open promoter in both normal cells and tissues, as well as in established cell lines. However, neither promoter was methylated in normal cells and tissues even when its transcripts were undetectable. Moreover, the Sgy promoter remained unmethylated as Sgy expression was repressed during ES cell differentiation. Therefore, DNA methylation was not the primary determinant of Sgy/Tead2 expression. Nevertheless, Sgy expression was consistently restricted to basal levels whenever downstream regulatory sequences were methylated, suggesting that DNA methylation restricts but does not regulate differential gene expression during mouse development. Intine, R. V., M. Dundr, A. Vassilev, E. Schwartz, Y. Zhou, Y. Zhao, M. L. DePamphilis, and R. J. Maraia (2004) Nonphosphorylated Human La Antigen Interacts With Nucleolin At Nucleolar Sites Involved In rRNA Biogenesis, Mol. Cell. Biol. 24:10894-904. La is an abundant RNA-binding protein that has been proposed to function in multiple pathways involved in the production of tRNAs, ribosomal proteins and other components of the translational machinery (Kenan and Keene, 2004 Nat Struct & Mol Biol, 11:306). Human (h)La is either phosphorylated or nonphosphorylated on serine-366 (S366, pLa & npLa, respectively). In addition to its conserved N-terminal domain, hLa contains a C-terminal domain that contains an atypical RNA recognition motif (RRM) and short basic motif (SBM), whose distinct mode of RNA binding is inhibited by S366 phosphorylation. We report that npLa is most concentrated in nucleolar foci that harbor fibrillarin, nucleolin, and nascent pol I transcripts. Immunoprecipitation of native or tagged hLa as well as yeast two hybrid analysis and fluorescence resonance energy transfer (FRET) in the nucleolus, reveals association with nucleolin. HLa lacking the SBM fails to localize to nucleoli and does not exhibit FRET with nucleolin. The data indicate that the nonphosphorylated SBM directs interaction with nucleolin, and provides evidence that the npLa specifically is involved in nucleolar biology related to ribosome biogenesis. DePamphilis, M.L. (2004) Mammalian Development, Regulation of Gene Expression in, in Meyers, R.A. (Ed.): Encyclopedia of Molecular Cell Biology and Molecular Medicine, volume 6, pp. ??, WILEY-VCH Verlag, Weinheim, Germany. (http://www.wiley-vch.de/books/emcbmm2/index.html)

Kohn，M.J.，K.J。 Kaneko和M.L. Dipamphilis（2005）DKKL1（潮湿）是Dickkopf家族成员，在哺乳动物的精子发生期间定位于Acrosome，Mol。复制。开发71：516-522。 dickkopf样1（DKKL1）与Dickkopf基因家族有关，Dickkopf基因家族是一组蛋白质，这些蛋白质被描述为无翼信号转导蛋白的分泌拮抗剂。 DKKL1 mRNA在植入前小鼠胚胎和发展神经组织中发现，但在成年人中主要发现在睾丸中。为了阐明其功能，通过免疫 - 归化学和免疫印象技术分析了小鼠睾丸和成熟精子中dickkopf样1蛋白（DKKL1）的分布。 DKKL1早在第十二阶段就首次出现在生精小管中的生理细胞中，与DKKL1 mRNA的出现相吻合。然而，令人惊讶的是，DKKL1本地定位于精子细胞和精子中的Actrosom，以及成熟精子中的Acrosome。此外，在睾丸中，dKKL1是N-糖基化的，但似乎没有排泄，并且成熟精子中的DKKL1不再是N-糖基化的，这表明在精子发生的最终阶段发生了其他翻译后修饰。这些结果将Dickkopf家族的成员识别为一种新型的粘体蛋白，可能参与Adrosomssbly或功能，这是分泌信号分子的独特作用。 Kaneko，K.J.，T。Rein，Z-S Guo，K。Latham和M.L. DEMPAMPHILIS。 （2004）DNA甲基化可能限制，但不能确定小鼠发育过程中SGY/TEAD2基因座的差异基因表达，mol。细胞。生物。 24：1968-1982。 在小鼠植入前胚胎和胚胎干细胞（ES）细胞中协调表达了两个与CpG岛的潮湿（SGY）和TEAD2，但在分化细胞中差异表达。对已建立的细胞系的分析表明，SGY基因表达可以通过SGY启动子的甲基化完全抑制，并且DNA甲基化与染色质脱乙酰化协同作用。差异基因表达与差异DNA甲基化相关，从而导致正常细胞和组织中的开放启动子以及既定的细胞系中从甲基化到未甲基化的DNA的急剧过渡。但是，即使无法检测到其转录本，启动子在正常细胞和组织中均未甲基化。此外，由于在ES细胞分化过程中抑制了SGY表达，因此SGY启动子仍然没有甲基化。因此，DNA甲基化不是SGY/TEAD2表达的主要决定因素。然而，每当下游调节序列被甲基化时，SGY表达始终仅限于基础水平，这表明DNA甲基化限制了小鼠发育过程中差异基因的表达。 Intine，R。V.，M。Dundr，A。Vassilev，E。Schwartz，Y。Zhou，Y。Zhao，M。L. Depamphilis和R. J. Maraia（2004）非磷酸化的人LA抗原与涉及RRNA生物发生的核仁位点的核仁素相互作用。细胞。生物。 24：10894-904。 LA是一种丰富的RNA结合蛋白，已提出在参与TRNA，核糖体蛋白和翻译机械的其他成分的多种途径中发挥作用（Kenan and Keene，2004 Nat Struct＆Mol Biol，11：306）。人（H）LA在丝氨酸-366（S366，PLA和NPLA）上被磷酸化或非磷酸化。除了其保守的N末端结构域外，HLA还包含一个C末端结构域，其中包含非典型RNA识别基序（RRM）和简短的基本基序（SBM），S366磷酸化抑制了其独特的RNA结合模式。我们报告说，NPLA最集中在含有纤维蛋白，核醇和新生pol I转录本的核仁灶中。核仁中的天然或标记的HLA的免疫沉淀以及酵母两种杂交分析和荧光共振能量转移（FRET）揭示了与核苷的关联。缺乏SBM的HLA未能定位于核仁，也不会用核仁素表现出FRET。数据表明，非磷酸化的SBM指导与核醇蛋白的相互作用，并提供证据表明NPLA专门参与与核糖体生物发生相关的核仁生物学。 Demamphilis，M.L。 （2004）哺乳动物的发育，在R.A. Meyers中对基因表达的调节。 （ed。）：分子细胞生物学和分子医学百科全书，第6卷，pp。??，Wiley-vch Verlag，德国温海姆。 （http://www.wiley-vch.de/books/emcbmm2/index.html）