Molecular cloning of POEM -: A novel adhesion molecule that interacts with α8β1 integrin
Molecular cloning of POEM -: A novel adhesion molecule that interacts with α8β1 integrin
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DOI：
10.1074/jbc.m103216200
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发表时间：
2001-11-09
影响因子：
4.8
通讯作者：
Tezuka, K
中科院分区：
文献类型：
--
作者：
Morimura, N;Tezuka, Y;Tezuka, K
细胞黏附分子参与多种生物学功能，如细胞存活、细胞分化、组织修复和发育等。根据已知的类表皮生长因子(EGF)基序设计了一组简并引物，通过逆转录-聚合酶链式反应(RT-PCR)获得了一个新的分子--POEM(带有meprin的前成骨细胞表皮生长因子样重复蛋白、A5蛋白和受体蛋白-酪氨酸磷酸酶Mu结构域)。从结构上看，POEM是一种新的黏附分子，具有5个EGF样结构域、一个Arg-GlyAsp(RGD)细胞结合基序、一个meprin、A5蛋白和受体蛋白-酪氨酸磷酸酶u(MAM)结构域。用胚胎16.5天(E16.5)的小鼠胚胎进行原位杂交，在发育中的肾小管、甲状旁腺、甲状腺、发育中的骨、牙胚和脑的内分泌器官中，POEM mRNA有较强的表达。内耳、骨骼肌、平滑肌(血管系统除外)和皮肤也呈POEM阳性表达。含有RGD序列和MAM结构域的细菌重组POEM蛋白具有很强的细胞黏附、铺展和促进存活的活性。通过将RGD序列突变为RGE，细胞的伸展和存活活性显著降低，但MAM结构域只对细胞黏附起作用，而对细胞没有影响。传播和促进生存活动。POEM在几种组织中的分布与α(8)、β(1)整合素的分布相近。因此，我们使用稳定表达α(8)整合素的K562白血病克隆细胞Ka8进行了细胞黏附试验。亲代K562细胞表达α(5)β(1)整合素，可与纤维连接蛋白结合，但不与POE结合。另一方面，Ka8细胞对纤维连接蛋白和PEN均表现出较强的结合和铺展能力。这些结果表明，POEM是一种新的α(8)β(1)整合素的配体，可能参与各种组织的发育和功能，如肾脏、骨骼、肌肉和内分泌器官。
Cell adhesion molecules are involved in a number of biological functions, such as cell survival, cell differentiation, tissue repair, and development. A novel molecule, POEM (preosteoblast epidermal growth factor-like repeat protein with meprin, A5 protein, and receptor protein-tyrosine phosphatase mu domain), was isolated by reverse transcription-polymerase chain reaction using a set of degenerate primers designed after other known epidermal growth factor (EGF)-like motifs. From its structure, POEM was suggested to be a novel adhesion molecule with five EGF-like domains, an Arg-GlyAsp (RGD) cell binding motif, and a meprin, A5 protein, and receptor protein-tyrosine phosphatase mu (MAM) domain. By in situ hybridization using embryonic day 16.5 (E16.5) mouse embryos, strong expression of POEM mRNA was observed in developing kidney renal tubules, parathyroid and thyroid glands, developing bone, tooth germ, and endocrine organs of the brain. The inner ear, skeletal muscle, smooth muscle (except for the vascular system), and skin were also positive for POEM expression. Bacterial recombinant POEM protein containing the RGD sequence and MAM domain showed strong cell adhesion, spreading, and survival-promoting activities. By mutating the RGD sequence to RGE, the cell spreading and survival activities were significantly decreased, but the MAM domain was shown to contribute only to cell adhesion and not to cell. spreading and survival-promoting activities. The distribution of POEM in several tissues was close to that of alpha (8)beta (1) integrin. Therefore, we conducted cell adhesion assays using KA8 cells, a K562 leukemia clone stably expressing alpha (8) integrin. Parental K562 cells, which expressed alpha (5)beta (1) integrin, bound to fibronectin but not to POEM. On the other hand, KA8 cells showed strong binding and spreading on both fibronectin and POEM. These results suggest that POEM is a novel ligand for alpha (8)beta (1) integrin and that POEM may be involved in the development and function of various tissues, such as kidney, bone, muscles, and endocrine organs.