Cleavage of apolipoprotein E by membrane-type matrix metalloproteinase-1 abrogates suppression of cell proliferation
Cleavage of apolipoprotein E by membrane-type matrix metalloproteinase-1 abrogates suppression of cell proliferation
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DOI：
10.1093/jb/mvi009
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发表时间：
2005-01-01
影响因子：
2.7
通讯作者：
Sato, H
中科院分区：
文献类型：
--
作者：
Aoki, T;Sato, D;Sato, H
使用表达克隆方法，将人胎脑 cDNA 文库中的载脂蛋白 E (apoE) 鉴定为与潜在基质金属蛋白酶 (MMP)-2 形成复合物的基因产物。 HEK293T 细胞中膜型 MMP-1 (MT1-MMP) 与 apoE 的共表达减少了分泌到培养基中的 apoE 量，而细胞相关的 apoE 核心蛋白不受影响。将天然 apoE 蛋白与重组 MT1-MMP 一起孵育，导致 apoE 裂解。与谷胱甘肽 S-转移酶融合的重组 apoE 蛋白 (apoE-GST) 被 MT1-AMP 在以下肽键处切割； T-85-M-86、K-93-S-94、R-246-L-247、A(255)-E-256 和 G(296)-L-297。转染apoE基因的HT1080细胞表达内源性MT1-AMP，分泌低水平的apoE蛋白及其裂解片段，用MMP抑制剂BB94处理可诱导apoE积累并抑制细胞增殖。在 HEK293T 细胞培养物中添加 apoE-GST 蛋白可抑制细胞增殖，稳定转染 MT1-AMP 基因可部分消除这种抑制。这些结果表明，MT1-MMP 对 apoE 蛋白的裂解消除了 apoE 介导的细胞增殖抑制。
Apolipoprotein E (apoE) in a human fetal brain cDNA library was identified, using the expression cloning method, as a gene product that formed a complex with latent matrix metalloproteinase (MMP)-2. Co-expression of membrane-type MMP-1 (MT1-MMP) with apoE in HEK293T cells reduced the amount of apoE secreted into the culture medium, whereas cell-associated apoE core protein was not affected. Incubation of native apoE protein with recombinant MT1-MMP resulted in the cleavage of apoE. Recombinant apoE protein fused to glutathione S-transferase (apoE-GST) was cleaved by MT1-AMP at the following peptide bonds; T-85-M-86, K-93-S-94, R-246-L-247, A(255)-E-256 and G(296)-L-297. HT1080 cells transfected with the apoE gene, which express endogenous MT1-AMP, secreted a low level of apoE protein and its cleaved fragments, and treatment with MMP inhibitor BB94 induced accumulation of apoE and retardation of cell proliferation. Addition of apoE-GST protein to the culture of HEK293T cells suppressed cell proliferation, and stable transfection of the MT1-AMP gene partly abrogated the suppression. These results suggest that cleavage of apoE protein by MT1-MMP abrogates apoE-mediated suppression of cell proliferation.