Molecular cloning of syndecan, an integral membrane proteoglycan.
Molecular cloning of syndecan, an integral membrane proteoglycan.
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DOI：
10.1083/jcb.108.4.1547
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发表时间：
1989-04
期刊：
影响因子：
--
通讯作者：
Bernfield M
中科院分区：
文献类型：
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作者：
Saunders S;Jalkanen M;O'Farrell S;Bernfield M
我们描述了一种细胞表面蛋白聚糖的cDNA克隆，该蛋白聚糖同时具有硫酸乙酰肝素和硫酸软骨素，并将细胞骨架连接到间质基质。该cDNA编码一个独特的32，868 D核心蛋白，该蛋白含有与其作为含糖胺聚糖基质锚的作用一致的几种结构特征。该序列显示出离散的细胞质、跨膜和NH 2末端细胞外结构域，表明该分子是I型整合膜蛋白。胞质结构域较小，大小相似，但序列与各种整联蛋白的β链不同。细胞外结构域包含与跨膜结构域的细胞外表面相邻的单个二元序列，潜在地充当参与该结构域从细胞表面释放的蛋白酶敏感位点。细胞外结构域含有两种不同类型的推定的糖胺聚糖附着位点;一种类型显示先前描述的硫酸软骨素附着位点的序列特征（Bourdon，M.一、T. Krusius，S.坎贝尔，N. B。Schwartz和E. Ruoslahti。1987. Proc. Natl. Acad. Sci. USA. 84：3194-3198），但另一种类型具有新鉴定的序列特征，其可能对应于硫酸乙酰肝素附着位点。单一的N-连接的糖识别序列是在假定的硫酸软骨素附着序列，表明天冬酰胺糖基化作为一种机制，调节硫酸软骨素链添加。该cDNA的5'和3'区具有与人胰岛素受体cDNA的类似区基本相同的序列：跨越5'非翻译区和初始编码序列的99-bp区的序列相同性为67%，3'非翻译区中的35- bp区的序列相同性为81%。mRNA表达具有组织特异性;各种上皮组织显示相同的两种大小的mRNA（2.6和3.4 kb）;在相同的相对丰度（3：1）下，大脑显示单一的4.5 kb mRNA。这种核心蛋白cDNA描述了一类新的分子，一种完整的膜蛋白聚糖，我们建议将其命名为syndecan（来自希腊语syndein，结合在一起）。
We describe cDNA clones for a cell surface proteoglycan that bears both heparan sulfate and chondroitin sulfate and that links the cytoskeleton to the interstitial matrix. The cDNA encodes a unique core protein of 32,868 D that contains several structural features consistent with its role as a glycosamino-glycan-containing matrix anchor. The sequence shows discrete cytoplasmic, transmembrane, and NH2-terminal extracellular domains, indicating that the molecule is a type I integral membrane protein. The cytoplasmic domain is small and similar in size but not in sequence to that of the beta-chain of various integrins. The extracellular domain contains a single dibasic sequence adjacent to the extracellular face of the transmembrane domain, potentially serving as the protease-susceptible site involved in release of this domain from the cell surface. The extracellular domain contains two distinct types of putative glycosaminoglycan attachment sites; one type shows sequence characteristics of the sites previously described for chondroitin sulfate attachment (Bourdon, M. A., T. Krusius, S. Campbell, N. B. Schwartz, and E. Ruoslahti. 1987. Proc. Natl. Acad. Sci. USA. 84:3194-3198), but the other type has newly identified sequence characteristics that potentially correspond to heparan sulfate attachment sites. The single N-linked sugar recognition sequence is within the putative chondroitin sulfate attachment sequence, suggesting asparagine glycosylation as a mechanism for regulating chondroitin sulfate chain addition. Both 5' and 3' regions of this cDNA have sequences substantially identical to analogous regions of the human insulin receptor cDNA: a 99-bp region spanning the 5' untranslated and initial coding sequences is 67% identical and a 35- bp region in the 3' untranslated region is 81% identical in sequence. mRNA expression is tissue specific; various epithelial tissues show the same two sizes of mRNA (2.6 and 3.4 kb); in the same relative abundance (3:1), the cerebrum shows a single 4.5-kb mRNA. This core protein cDNA describes a new class of molecule, an integral membrane proteoglycan, that we propose to name syndecan (from the Greek syndein, to bind together).