Homologs of the Xenopus developmental gene DG42 are present in zebrafish and mouse and are involved in the synthesis of Nod-like chitin oligosaccharides during early embryogenesis.
Homologs of the Xenopus developmental gene DG42 are present in zebrafish and mouse and are involved in the synthesis of Nod-like chitin oligosaccharides during early embryogenesis.
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非洲爪蟾发育基因 DG42 的同源物存在于斑马鱼和小鼠中，并参与早期胚胎发生过程中 Nod 样几丁质寡糖的合成。
DOI：
10.1073/pnas.93.10.4548
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发表时间：
1996
影响因子：
11.1
通讯作者：
Robbins,PW
中科院分区：
文献类型：
--
作者：
Semino,CE;Specht,CA;Raimondi,A;Robbins,PW
非洲爪蟾发育基因DG 42在胚胎发育早期即中胚期和神经胚形成期之间表达。推测的爪蟾DG 42蛋白序列与根瘤菌Nod C、链球菌Has A和真菌几丁质酶具有相似性。在此之前，我们发现DG 42蛋白在体外转录/翻译系统中催化合成一系列几丁质寡糖。在这里，我们表明，早期爪蟾和斑马鱼胚胎的细胞提取物也合成壳寡糖。另外还克隆了斑马鱼和小鼠DG 42的cDNA同源片段并进行了序列测定。这些同源物的表达类似于基于北方和Western印迹分析的爪蟾的表达。非洲爪蟾抗DG 42抗体识别的63 kDa的蛋白质提取物从斑马鱼胚胎，遵循类似的发育表达模式，以前描述的非洲爪蟾。提取物中发现的几丁质寡糖合酶活性被特定DG 42抗体灭活;在测试条件下，透明质酸（HA）的合成不受影响。其它实验证明，在小鼠3 T3细胞中质粒控制下DG 42的表达引起壳寡糖合酶活性而不增加HA合酶水平。我们的研究结果和其他研究人员的结果之间可能存在关系，这些研究结果显示在哺乳动物细胞培养系统中DG 42对HA合成的刺激，这一关系由其他地方发表的结构分析提供，该分析表明甲壳素寡糖存在于HA链的还原末端。由于在至少一种脊椎动物系统中透明质酸的形成可以被纯几丁质酶抑制，因此几丁质寡糖似乎可以用作透明质酸合成的引物。
The Xenopus developmental gene DG42 is expressed during early embryonic development, between the midblastula and neurulation stages. The deduced protein sequence of Xenopus DG42 shows similarity to Rhizobium Nod C, Streptococcus Has A, and fungal chitin synthases. Previously, we found that the DG42 protein made in an in vitro transcription/translation system catalyzed synthesis of an array of chitin oligosaccharides. Here we show that cell extracts from early Xenopus and zebrafish embryos also synthesize chitooligosaccharides. cDNA fragments homologous to DG42 from zebrafish and mouse were also cloned and sequenced. Expression of these homologs was similar to that described for Xenopus based on Northern and Western blot analysis. The Xenopus anti-DG42 antibody recognized a 63-kDa protein in extracts from zebrafish embryos that followed a similar developmental expression pattern to that previously described for Xenopus. The chitin oligosaccharide synthase activity found in extracts was inactivated by a specific DG42 antibody; synthesis of hyaluronic acid (HA) was not affected under the conditions tested. Other experiments demonstrate that expression of DG42 under plasmid control in mouse 3T3 cells gives rise to chitooligosaccharide synthase activity without an increase in HA synthase level. A possible relationship between our results and those of other investigators, which show stimulation of HA synthesis by DG42 in mammalian cell culture systems, is provided by structural analyses to be published elsewhere that suggest that chitin oligosaccharides are present at the reducing ends of HA chains. Since in at least one vertebrate system hyaluronic acid formation can be inhibited by a pure chitinase, it seems possible that chitin oligosaccharides serve as primers for hyaluronic acid synthesis.