Phorbol ester-induced shedding of the prostate cancer marker transmembrane protein with epidermal growth factor and two follistatin motifs 2 is mediated by the disintegrin and metalloproteinase-17
Phorbol ester-induced shedding of the prostate cancer marker transmembrane protein with epidermal growth factor and two follistatin motifs 2 is mediated by the disintegrin and metalloproteinase-17
复制标题
DOI：
10.1074/jbc.m702170200
复制
发表时间：
2007-12-28
影响因子：
4.8
通讯作者：
Knaeuper, Vera
中科院分区：
文献类型：
--
作者：
Ali, Nazim;Knaeuper, Vera
具有表皮生长因子和两个卵泡抑素基序2（TMEFF 2）的跨膜蛋白在前列腺和脑中表达，并以金属蛋白酶依赖的方式从细胞表面脱落。负责TMEFF 2脱落的脱落酶和可溶性TMEFF 2胞外域（TMEFF 2-ECD）的生理学意义或活性均未被鉴定。在本研究中，我们提出了新的证据表明，解整合素和金属蛋白酶-17（ADAM 17）是负责佛波醇12-肉豆蔻酸酯13-乙酸酯诱导的释放TMEFF 2-ECD使用小干扰RNA消融ADAM 17的表达或通过抑制酶活性。监测碱性磷酸酶标记的TMEFF2-ECD释放到培养基中以及裂解物中22-和14-kDa C-末端片段的产生的单孔脱落测定依赖于ADAM 17活性。一种γ-分泌酶抑制剂阻止了细胞裂解物中10-kDa片段的形成，从而建立了TMEFF 2作为一种新型底物，用于调节膜内蛋白水解。我们将增殖诱导活性分配给TMEFF 2。使用合成金属蛋白酶抑制剂或靶向TMEFF 2表达的小干扰RNA抑制TMEFF 2脱落，在淋巴结来源的前列腺癌细胞（LNCaPs）和过表达TMEFF 2的人胚肾（HEK293）细胞系中产生了统计学显著的细胞增殖减少。TMEFF2-ECD能够以表皮生长因子受体（或ErbB1）依赖性方式诱导HEK293细胞中ERK 1/2磷酸化。我们的数据表明，TMEFF 2有助于细胞增殖的ADAM 17依赖性自分泌的方式在细胞表达这种蛋白质。
The transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2) is expressed in prostate and brain and shed from the cell surface in a metalloproteinase-dependent fashion. Neither the sheddase(s) responsible for TMEFF2 shedding nor the physiological significance or activity of the soluble TMEFF2 ectodomain (TMEFF2-ECD) has been identified. In the present study we present new evidence that a disintegrin and metalloproteinase-17 (ADAM17) is responsible for phorbol 12-myristate 13-acetate-induced release of TMEFF2-ECD using small interfering RNA to ablate ADAM17 expression or by inhibiting enzymatic activity. A single well shedding assay monitoring the release of alkaline phosphatase-tagged TMEFF2-ECD into medium and the generation of 22- and 14-kDa C-terminal fragments in lysates were dependent on ADAM17 activity. A gamma-secretase inhibitor prevented the formation of a 10-kDa fragment in cell lysates, thus establishing TMEFF2 as a novel substrate for regulated intramembrane proteolysis. We assigned proliferation-inducing activity to TMEFF2. Inhibition of TMEFF2 shedding using synthetic metalloproteinase inhibitors or small interfering RNA targeting TMEFF2 expression yielded a statistically significant reduction of cell proliferation in the lymph node-derived prostate cancer cells (LNCaPs) and a human embryonic kidney (HEK293) cell line overexpressing TMEFF2. The TMEFF2-ECD was able to induce ERK1/2 phosphorylation in an epidermal growth factor receptor(or ErbB1)-dependent manner in HEK293 cells. Our data suggest that TMEFF2 contributes to cell proliferation in an ADAM17-dependent autocrine fashion in cells expressing this protein.