Zhang Guangji, Zhang Jinrui, Li Xiang, Meng Xin, Fang Xuexun
Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University 2699 Qianjin Street Changchun 130012 PR China
RSC Adv. 2019 Jul 25;9(40):23053-23060. doi: 10.1039/c9ra05222d. eCollection 2019 Jul 23.
Matrix metalloproteinase 26 (MMP-26), also called endometase and matrilysin-2, belongs to the MMP superfamily. Previous studies have focused on its role in tumor invasion and migration but detailed subcellular localization of MMP-26 remains poorly understood. In this study, sequence deletion mutants of MMP-26 revealed that residues 88-123 function to localize MMP-26 to the endoplasmic reticulum (ER). Moreover, using homologous recombination, we show that exchanging residues 88-123 of secretory MMP-7 with the same region in MMP-26 causes localization of this MMP-7 construct to the ER. Moreover, two (N64, N221) of the three possible -glycosylation sites in MMP-26 were shown to be -glycosylated, and -glycosylation is not required for ER localization. These results demonstrate that the 88-123 region of MMP-26 is a noncanonical ER retention signal and MMP-26 is an -glycosylated protein, thereby providing novel insights into the properties of MMP-26 within the cell.
基质金属蛋白酶26（MMP - 26），也被称为子宫内膜酶和基质溶素 - 2，属于MMP超家族。以往的研究集中在其在肿瘤侵袭和迁移中的作用，但MMP - 26详细的亚细胞定位仍知之甚少。在本研究中，MMP - 26的序列缺失突变体表明，88 - 123位残基的功能是将MMP - 26定位于内质网（ER）。此外，通过同源重组，我们发现将分泌型MMP - 7的88 - 123位残基与MMP - 26中的相同区域进行交换会导致该MMP - 7构建体定位于内质网。此外，MMP - 26三个可能的N - 糖基化位点中的两个（N64、N221）被证明发生了N - 糖基化，并且N - 糖基化对于内质网定位不是必需的。这些结果表明，MMP - 26的88 - 123区域是一个非典型的内质网滞留信号，并且MMP - 26是一种N - 糖基化蛋白，从而为细胞内MMP - 26的特性提供了新的见解。
