Ogt-dependent X-chromosome-linked protein glycosylation is a requisite modification in somatic cell function and embryo viability
Ogt-dependent X-chromosome-linked protein glycosylation is a requisite modification in somatic cell function and embryo viability
复制标题
DOI：
10.1128/mcb.24.4.1680-1690.2004
复制
发表时间：
2004-02-01
影响因子：
5.3
通讯作者：
Marth, JD
中科院分区：
文献类型：
--
作者：
O'Donnell, N;Zachara, NE;Marth, JD
Ogt基因编码将N-乙酰葡糖胺连接到核和胞质蛋白上的丝氨酸和苏氨酸残基（O-GlcNAc）的糖基转移酶。研究哺乳动物Ogt缺陷模型的努力受到胚胎干细胞活力中X连锁基因的要求的阻碍，需要在体内使用条件诱变。我们已经扩大了这些观察隔离OGT突变不同的体细胞类型，包括神经元，胸腺细胞，成纤维细胞，后者的方法开发的诱导OGT诱变。我们发现Ogt突变导致O-GlcNAc的丢失，并导致T细胞凋亡，神经元tau蛋白过度磷酸化，成纤维细胞生长停滞，c-Fos，c-Jun，c-Myc，Sp1和p27的表达改变。我们进一步分离的突变Ogt等位基因的亲本配子卵母细胞和精子特异性Cre-loxP诱变。通过这一点，我们建立了一个体内遗传学的方法，支持个体发育的女性杂合子携带突变的X-连锁基因在胚胎发生过程中所需的。这种雌性杂合子的成功产生和表征进一步表明哺乳动物细胞通常需要功能性Ogt等位基因。我们发现，O-GlcNAc调节蛋白质磷酸化和表达之间的必要和保守的细胞信号传导途径。
The Ogt gene encodes a glycosyltransferase that links N-acetylglucosamine to serine and threonine residues (O-GlcNAc) on nuclear and cytosolic proteins. Efforts to study a mammalian model of Ogt deficiency have been hindered by the requirement for this X-linked gene in embryonic stem cell viability, necessitating the use of conditional mutagenesis in vivo. We have extended these observations by segregating Ogt mutation to distinct somatic cell types, including neurons, thymocytes, and fibroblasts, the latter by an approach developed for inducible Ogt mutagenesis. We show that Ogt mutation results in the loss of O-GlcNAc and causes T-cell apoptosis, neuronal tau hyperphosphorylation, and fibroblast growth arrest with altered expression of c-Fos, c-Jun, c-Myc, Sp1, and p27. We further segregated the mutant Ogt allele to parental gametes by oocyte- and spermatid-specific Cre-loxP mutagenesis. By this we established an in vivo genetic approach that supports the ontogeny of female heterozygotes bearing mutant X-linked genes required during embryogenesis. Successful production and characterization of such female heterozygotes further indicates that mammalian cells commonly require a functional Ogt allele. We find that O-GlcNAc modulates protein phosphorylation and expression among essential and conserved cell signaling pathways.