Functional Analyses of Genes from Mouse t complex in Chromosome 17

小鼠 17 号染色体 t 复合体基因的功能分析

• 批准号: 6227828
• 负责人: Minoru S Ko
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 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/6227828
• 关键词: adenosine triphosphate; animal genetic material tag; antisense nucleic acid; binding proteins; chromosome deletion; chromosomes; developmental genetics; genome; genomic imprinting; guanine nucleotide binding protein; laboratory mouse; lethal genes; mammalian embryology; sperm; striated muscles

The proximal half of the mouse chromosome 17, called t-complex, encompasses ~30 Mb of mouse genome and contains many loci that cause abnormalities in embryonic development and male germ cell function, as well as two genes proven to be imprinted (Ifg2r, Mas1). When we placed on the mouse genetic map 155 new genes randomly chosen from the extraembryonic tissues of E7.5 mouse embryos, 10 genes were found clustered in this mouse t-complex. A second series of gene mappings with 800 new genes from preimplantation mouse embryos localized an additional 16 genes to this region. To examine whether these genes may be candidates for t-complex mouse embryonic lethals, these genes were further characterized more in detail.The gene characterized is D17Wsu11e. It was renamed Nucleotide binding protein 2 (Nubp2) because the gene encodes a protein with an ATP/GTP-binding motif. Based on sequence similarity, another gene was cloned and named Nucleotide binding protein 1 (Nubp1). Phylogenetic analyses of the genes, which encode a short form (Nubp2) and long form (Nubp1) of NUBP, clearly establish them as a new NUBP/MRP gene family that is well conserved throughout phylogeny. Mouse Nubp2 is mapped to the t-complex region of mouse Chromosome 17, whereas Nubp1 is mapped to the proximal region of mouse Chromosome 16. Interestingly, both regions are syntenic with human Chromosome 16p13.1-p13.3, suggesting that a chromosomal breakage probably occurred during the evolution of mouse chromosomes between Nubp2 and Nubp1. Knockouts of yeast orthologs of these two genes were not viable, suggestive of the essential functions for these two genes.A second gene analyzed thus far is D17Wsu134e, which was renamed Rsk3 based on the presence of human ortholog, pp90rsk(Ser/Thr) kinase (RSK3). The protein carries two non-identical kinase domains in tandem: the C-terminal kinase is thought to upregulate the N-terminal kinase that phosphorylates the exogenous substrates. Expression of the Rsk3 gene was examined during the mouse development and in different adult organs. A low level of 5.0 kb Rsk3 transcript was observed in E7 embryos. Its expression was dramatically increased at E11 and dropped at E15 and E17 embryos, suggesting a critical function of the gene during mouse development. Among adult tissues, the highest expression was observed in skeletal muscle, but the gene was also expressed in a restricted number of other tissues, including heart, brain, lung, and testis. We are examining possible roles for the mouse Rsk3 gene using anti-sense and gene disruption techniques. - developmental genes; embryonic development; extraembryonic tissue; embryonic lethals

小鼠17号染色体的近端一半，称为t复合体，包含约30 Mb的小鼠基因组，包含许多导致胚胎发育和雄性生殖细胞功能异常的基因座，以及两个被证明是印记的基因（Ifg2r，Mas1）。当我们将从E7.5小鼠胚胎的胚外组织中随机选择的155个新基因放在小鼠遗传图谱上时，发现10个基因聚集在这个小鼠t复合体中。第二个系列的基因定位与800个新的基因，从植入前小鼠胚胎定位额外的16个基因到这个区域。为了检验这些基因是否可能是t-复合体小鼠胚胎致死的候选基因，进一步更详细地表征了这些基因。它被重新命名为核苷酸结合蛋白2（Nubp2），因为该基因编码具有ATP/GTP结合基序的蛋白质。基于序列相似性，克隆了另一个基因，命名为核苷酸结合蛋白1（Nubp1）。系统发育分析的基因，其中编码短形式（Nubp2）和长形式（Nubp1）的NUBP，清楚地建立他们作为一个新的NUBP/MRP基因家族，是很好地保守在整个进化。小鼠Nubp2定位于小鼠17号染色体的t复合体区域，而Nubp1定位于小鼠16号染色体的近端区域。有趣的是，这两个区域都与人类染色体16p13.1-p13.3同线，这表明在Nubp2和Nubp1之间的小鼠染色体进化过程中可能发生了染色体断裂。敲除这两个基因的酵母直向同源物是不可行的，提示这两个基因的基本功能。到目前为止分析的第二个基因是D17Wsu134e，基于人类直向同源物pp90rsk（Ser/Thr）激酶（RSK3）的存在，将其重命名为Rsk3。该蛋白携带两个串联的不同激酶结构域：C-末端激酶被认为上调使外源底物磷酸化的N-末端激酶。在小鼠发育过程中和不同的成年器官中检测Rsk3基因的表达。在E7胚胎中观察到低水平的5.0kb Rsk3转录本。它的表达在E11显著增加，在E15和E17胚胎下降，表明该基因在小鼠发育过程中的关键功能。在成人组织中，最高的表达是在骨骼肌中观察到的，但该基因也在有限数量的其他组织中表达，包括心脏、脑、肺和睾丸。我们正在使用反义和基因破坏技术研究小鼠Rsk3基因的可能作用。- 发育基因;胚胎发育;胚外组织;胚胎致死