整合素相互作用
中文名称
通路描述
整合素是一类 I 型跨膜蛋白，其 N 端胞外结构域包含几个糖胺聚糖 (GAG) 结合位点，C 端胞质结构域较短。整合素 -1 和 -3 的结合位点分别位于 N 端附近和膜结合位点附近，两者之间由富含脯氨酸和丝氨酸的'间隔区'隔开。整合素胞外结构域在家族和物种间保守性差，但跨膜和胞质结构域高度保守。整合素 -1 和 -3 形成亚家族。整合素核心蛋白形成二聚体 (Choi et al. 2007)，至少整合素 -3 和 -4 形成寡聚体 (Asundi & Carey 1995, Shin et al. 2012)。整合素 -1 是上皮细胞中主要的整合素，包括血管内皮细胞。整合素 -2 主要存在于间质细胞、神经细胞和平滑肌细胞中。整合素 -3 是神经系统的主要整合素，而整合素 -4 普遍表达但水平较低 (Alexopoulou et al. 2007)。整合素核心蛋白含有 3 到 5 条硫酸肝素或硫酸软骨素链，可与多种配体相互作用，包括成纤维细胞生长因子、血管内皮生长因子、转化生长因子 -β、纤连蛋白、胶原蛋白、粘蛋白和多种整合素。整合素可能作为整合素核心配体。纤连蛋白与整合素之间的相互作用受 Tenascin-C 调节。整合素结合多种可溶性和不溶性配体，包括细胞外基质成分、细胞粘附分子、生长因子、细胞因子和蛋白酶。由于整合素切割后的胞外结构域仍具有结合配体的能力，胞外结构域脱落是一种释放可溶性效应分子以与其细胞结合配体竞争的方法 (Kainulainen et al. 1998)。脱落后的胞外结构域存在于炎症液体中 (Subramanian et al. 1997)，并可能诱导癌细胞增殖 (Maeda et al. 2004)。
英文描述
Syndecan interactions Syndecans are type I transmembrane proteins, with an N-terminal ectodomain that contains several consensus sequences for glycosaminoglycan (GAG) attachment and a short C-terminal cytoplasmic domain. Syndecan-1 and -3 GAG attachment sites occur in two distinct clusters, one near the N-terminus and the other near the membrane-attachment site, separated by a proline and threonine-rich 'spacer'. Syndecan ectodomain sequences are poorly conserved in the family and between species, but the transmembrane and cytoplasmic domains are highly conserved. Syndecan-1 and -3 form a subfamily. Syndecan core proteins form dimers (Choi et al. 2007) and at least syndecan-3 and -4 form oligomers (Asundi & Carey 1995, Shin et al. 2012). Syndecan-1 is the major syndecan of epithelial cells including vascular endothelium. Syndecan-2 is present mostly in mesenchymal, neuronal and smooth muscle cells. Syndecan-3 is the major syndecan of the nervous system, while syndecan-4 is ubiquitously expressed but at lower levels than the other syndecans (refs in Alexopoulou et al. 2007). The core syndecan protein has three to five heparan sulfate or chondroitin sulfate chains, which interact with a variety of ligands including fibroblast growth factors, vascular endothelial growth factor, transforming growth factor-beta, fibronectin, collagen, vitronectin and several integrins. Syndecans may act as integrin coreceptors. Interactions between fibronectin and syndecans are modulated by tenascin-C. Syndecans bind a wide variety of soluble and insoluble ligands, inckluding extracellular matrix components, cell adhesion molecules, growth factors, cytokines, and proteinases. As the cleaved ectodomains of syndecans retain the ability to bind ligands, ectodomain shedding is a mechanism for releasing soluble effectors that may compete for ligands with their cell-bound counterparts (Kainulainen et al. 1998). Shed ectodomains are found in inflammatory fluids (Subramanian et al. 1997) and may induce the proliferation of cancer cells (Maeda et al. 2004).
所含基因
23 个基因