Shedding of kidney injury molecule-1 by membrane-type 1 matrix metalloproteinase
Shedding of kidney injury molecule-1 by membrane-type 1 matrix metalloproteinase
复制标题
DOI：
10.1093/jb/mvs082
复制
发表时间：
2012-11-01
影响因子：
2.7
通讯作者：
Sato, Hiroshi
中科院分区：
文献类型：
--
作者：
Guo, Luyang;Takino, Takahisa;Sato, Hiroshi
膜型1基质金属蛋白酶（MT1-MMP）与肾损伤分子-1 （KIM-1）在HEK293T细胞中的共表达导致KIM-1外畴的分裂和脱落。利用KIM-1突变体分析裂解产物，将裂解位点定位在膜旁区域。用KIM-1或其近膜区缺失的突变体(Asp（261)-Gly(295)）表达质粒稳定转染HT1080细胞，分别建立HT/KIM-1或HT/Delta KIM-1细胞。在HT/KIM-1细胞中，KIM-1蛋白低水平出现在细胞表面，并通过MMP抑制剂BB-94或小干扰RNA （small interfering RNA, siRNA）作用于MT1-MMP而积累，表明MT1-MMP参与了KIM-1的裂解和脱落。相比之下，无论BB-94或siRNA处理，HT/Delta KIM-1细胞都高水平表达KIM-1蛋白。与KIM-1阴性细胞相比，表达高水平KIM-1蛋白的细胞表现出对大肠杆菌的吞噬作用，并减少了细胞在胶原包被板上的粘附和扩散。对照HT1080和HT/KIM-1细胞在胶原凝胶中的侵袭性生长、胶原包被板上的细胞迁移和鸡胚肝转移均显著高于HT/Delta KIM-1细胞。这些结果表明，KIM-1通过与胶原的相互作用负调控细胞功能，而MT1-MMP通过KIM-1的裂解和脱落来消除它。
Co-expression of membrane-type 1 matrix metalloproteinase (MT1-MMP) with kidney injury molecule-1 (KIM-1) in HEK293T cells resulted in cleavage and shedding of KIM-1 ectodomain. Analysis of cleavage products using KIM-1 mutants localized cleavage site at the juxtamembrane region. HT1080 cells were stably transfected with expression plasmid for KIM-1 or its mutant with deletion of the juxtamembrane region (Asp(261)-Gly(295)) to establish HT/KIM-1 or HT/Delta KIM-1 cells, respectively. KIM-1 protein appeared on cell surface at low level in HT/KIM-1 cells, and accumulated by the treatment with MMP inhibitor BB-94 or small interfering RNA (siRNA) to MT1-MMP, indicating that MT1-MMP is involved in cleavage and shedding of KIM-1. In contrast, HT/Delta KIM-1 cells expressed KIM-1 protein at high level regardless of BB-94 or siRNA treatment. Cells expressing high level KIM-1 protein exhibited phagocytosis of Escherichia coli and reduced cell adhesion and spreading on collagen-coated plate compared with KIM-1 negative cells. Control HT1080 and HT/KIM-1 cells showed significantly higher invasive growth in collagen gel, cell migration on collagen-coated plate and liver metastasis in chick embryo than HT/Delta KIM-1 cells. These results suggest that KIM-1 negatively regulates cellular function mediated through interaction with collagen, and MT1-MMP abrogates it through the cleavage and shedding of KIM-1.