Role for Sez12 in migration of cranial neural crest cells

Sez12 在颅神经嵴细胞迁移中的作用

• 批准号: 10671714
• 负责人: KAJIWARA Kagemasa
• 金额: $ 2.11万
• 依托单位: Tokai University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10671714/
• 关键词: DiGeorge syndrome; c-Ets1; craniofacial development; Sez12; retinoic acid; gene targeting; ganglioside; ノックアウトマウス; 神経冠細胞

SEZ-12 is a seizure-related mouse cDNA whose expression level is down-regulated by a convulsant drug, pentylenetetrazol, both in cultured cerebral neurons and in adult brain. Sequence analysis of SEZ-12 shows a significant homology to a human cDNA, named DGCR2/IDD/LAN, isolated from the chromosome 22q11.2 region critical for the DiGeorge syndrome. Here we determined the chromosomal localization of SEZ-12 gene, Sez12, by interspecific backcross analysis. Sez12 mapped on the proximal region of mouse chromosome 16 homologous to the human chromosome 22q11. RNA blotting and whole mount in situ hybridization of Sez12 mRNA showed a relative abundance in craniofacial region during mouse embryogenesis. To further determine the molecular mechanism underlying this expression, the deletion constructs of the Sez12 promoter were transfected into NIH3T3 cells. The results revealed an essential domain (-180 to -1) which included a cis-acting element for the transcription factor c-Ets1 and was upregulated its transcriptional activity by retinoic acid. Moreover, we showed that Sez12 products expressed in Xenopus oocytes were induced a large inward current by extracellular application of an oligosaccharide ligand, ganglioside glycolipid, suggesting that the Sez12 protein is a key effector whose interaction with some cell-surface ligands result in normal cellular development during embryogenesis. Taken together, Sez12 may play an important role in craniofacial development and that haploinsufficiency of this human homologue may be related in part to pathogenesis of DiGeorge syndrome. Now, to directly understand the physiological role of Sez12 in the animal, a null mutation has been introduced into the gene by homologous recombination in mouse embryonic stem cells.

SEZ-12是一种惊厥相关的小鼠cDNA，其表达水平在培养的脑神经元和成人脑中均被惊厥药物戊四氮下调。SEZ-12的序列分析显示与从DiGeorge综合征关键的染色体22q11.2区域分离的名为DGCR 2/IDD/LAN的人cDNA具有显著的同源性。本研究通过种间回交分析确定了SEZ-12基因Sez 12的染色体定位。Sez 12定位于小鼠16号染色体的近端区域，与人类染色体22 q11同源。RNA印迹和整体原位杂交显示，在小鼠胚胎发育的颅面区域的Sez 12 mRNA的相对丰度。为了进一步确定这种表达的分子机制，将Sez 12启动子的缺失构建体转染到NIH 3 T3细胞中。结果显示，一个必需的结构域（-180到-1），其中包括一个转录因子c-Ets 1的顺式作用元件，并上调其转录活性的视黄酸。此外，我们发现，在非洲爪蟾卵母细胞中表达的Sez 12产品诱导了一个大的内向电流的寡糖配体，神经节苷脂的细胞外应用，这表明Sez 12蛋白是一个关键的效应器，其与一些细胞表面配体的相互作用导致在胚胎发育过程中正常的细胞发育。总之，Sez 12可能在颅面发育中发挥重要作用，这种人类同源物的单倍不足可能与DiGeorge综合征的发病机制部分相关。现在，为了直接了解Sez 12在动物中的生理作用，通过小鼠胚胎干细胞中的同源重组将无效突变引入该基因。

项目成果

Kagemasa Kajiwara: "Sez4 gene encoding an elongation subunit of DNA polymerase zeta is required for normal embryogenesis"Genes to Cells. (印刷中). (2001)

Kagemasa Kajiwara：“正常胚胎发生需要编码 DNA 聚合酶 zeta 延伸亚基的 Sez4 基因”（正在出版）。

Kengo Tomita: "Gene structure and promoter for Crad2 encoding mouse cis-retinol/3alpha-hydroxysterol short-chain dehydrogenase isozyme"Gene. 251. 175-186 (2000)

Kengo Tomita：“Crad2 编码小鼠顺式视黄醇/3α-羟基甾醇短链脱氢酶同工酶的基因结构和启动子”基因。

Kiyoko Kawamura: "The error-prone DNA polymerase zeta catalytic subunit (Rev3) gene is ubiquitously expressed in normal and malignant human tissues"Int.J.Oncol.. 18. 97-103 (2001)

Kiyoko Kawamura：“容易出错的 DNA 聚合酶 zeta 催化亚基 (Rev3) 基因在正常和恶性人体组织中普遍表达”Int.J.Oncol.. 18. 97-103 (2001)

Shigeharu Wakana: "Gene mapping of SEZ group genes and determination of pentylenetetrazole susceptible quantitative trait loci in the mouse chromosome"Brain Research. (印刷中).

Shigeharu Wakana：“SEZ 组基因的基因定位和小鼠染色体中戊四唑易感数量性状位点的测定”《大脑研究》（出版中）。