Identification and characterization of matrix metalloproteinase-20 (MMP20; enamelysin) genes in reptile and amphibian.
Identification and characterization of matrix metalloproteinase-20 (MMP20; enamelysin) genes in reptile and amphibian.
复制标题
DOI：
10.1016/j.gene.2006.11.014
复制
发表时间：
2007-05
期刊：
影响因子：
3.5
通讯作者：
S. Shintani;Mitsuhiko Kobata;N. Kamakura;S. Toyosawa;T. Ooshima
中科院分区：
文献类型：
--
作者：
S. Shintani;Mitsuhiko Kobata;N. Kamakura;S. Toyosawa;T. Ooshima
基质金属蛋白酶-20（MMP 20;釉质溶解素）对于釉质形成期间细胞外基质（ECM）蛋白的蛋白水解加工是重要的，并且在釉质原蛋白（AMEL）（最丰富的釉质ECM蛋白）的蛋白水解加工中起关键作用。MMP 20可能在牙齿的出现中发挥了作用，因为外部骨骼上有原始牙齿的无颌脊椎动物可能拥有MMP 20基因，并且MMP 20和釉质ECM蛋白被认为随着时间的推移以一种特殊的关系一起进化。因此，了解MMP 20基因的分子进化对于阐明釉质的进化是重要的，并且有必要鉴定非哺乳动物中MMP 20基因的直系同源物，因为它已经在哺乳动物中鉴定。在本研究中，从爬行动物（凯门鳄）和两栖动物（非洲爪蟾）的MMP 20基因的直系同源物进行了克隆和鉴定。直向同源物的比较显示，MMP 20蛋白在整个四足动物进化过程中高度保守。此外，凯门鳄、蟾蜍和哺乳动物MMP 20具有一些特定于MMP 20的独特特征，但不具有其他基质金属蛋白酶的特征。此外，蟾蜍MMP 20基因只在上颚转录，可能是在牙齿中。这些结果表明，在四足动物的共同祖先中，MMP 20可能被招募用于AMEL的加工，并在3.5亿年的进化中被保存下来。
Matrix metalloproteinase-20 (MMP20; enamelysin) is important for proteolytic processing of extracellular matrix (ECM) proteins during the formation of enamel and plays a critical role in proteolytic processing of amelogenin (AMEL), the most abundant enamel ECM protein. MMP20 might have played a role in the emergence of teeth, because jawless vertebrates with primordial teeth on their external skeletons may have possessed the MMP20 gene, and MMP20 and enamel ECM proteins are thought to have evolved together in a special relationship over time. Thus, an understanding of the molecular evolution of the MMP20 gene is important for elucidating the evolution of enamel and it is necessary to identify the orthologs of the MMP20 gene in non-mammals, as it has been identified in mammals. In the present study, orthologs of the MMP20 genes from a reptile (caiman) and an amphibian (African clawed toad) were cloned and characterized. Comparisons of the orthologs revealed that the MMP20 proteins were highly conserved throughout the evolution of tetrapods. Further, the caiman, toad, and mammalian MMP20 shared several unique features specific for MMP20, but not for other matrix metalloproteinases. In addition, the toad MMP20 gene was transcribed only in the upper jaw, presumably in teeth. These results suggest that MMP20 in a common ancestor of tetrapods might have been recruited for the processing of AMEL and conserved over 350 million years of evolution.