Collagen XVIII is a basement membrane heparan sulfate proteoglycan
Collagen XVIII is a basement membrane heparan sulfate proteoglycan
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DOI：
10.1074/jbc.273.39.25404
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发表时间：
1998-09-25
影响因子：
4.8
通讯作者：
Cole, GJ
中科院分区：
文献类型：
--
作者：
Halfter, W;Dong, SC;Cole, GJ
本研究表明，XVIII胶原是继perlecan和agrin之后的第三个基层硫酸肝素蛋白聚糖（HSPG），也是第一个具有硫酸肝素侧链的胶原/蛋白聚糖。利用鸡HSPG单克隆抗体，从鸡卵黄囊文库中分离到14个cDNA克隆。所有克隆均具有与小鼠和人XVIII胶原同源的共同核苷酸序列。鸡片段的氨基酸序列与人类和小鼠的XVIII胶原蛋白有83%的同源性。鸡胶原XVIII mRNA与人类和小鼠同源物相似，大小为4.5千碱基对。在Western blot中，胶原XVIII出现为分子质量为300 kDa的涂片。经肝素酶处理后，蛋白分子质量减少了120 kDa，蛋白核为180 kDa。XVIII胶原具有胶原的典型特征，如在非变性条件下作为非共价连接的低聚物存在，以及核心蛋白对胶原酶消化的敏感性。它还具有HSPG的特征，如长肝素酶敏感的碳水化合物链和高度负的净电荷。胶原XVIII大量存在于视网膜基底层、表皮、眼球、心脏和横纹肌、肾脏、血管和肺中。原位杂交结果表明，XVIII: HSPG蛋白在鸡胚中主要表达于肾脏和周围神经系统。作为底物，XVIII胶原适度促进雪旺细胞的粘附，但对周围神经系统神经元和轴突没有这种活性。
The present study shows that collagen XVIII is, next to perlecan and agrin, the third basal lamina heparan sulfate proteoglycan (HSPG) and the first collagen/proteoglycan with heparan sulfate side chains. By using monoclonal antibodies to an unidentified HSPG in chick, 14 cDNA clones were isolated from a chick yolk sac library. All clones had a common nucleotide sequence that was homologous to the mRNA sequences of mouse and human collagen XVIII. The deduced amino acid sequence of the chick fragment shows an 83% overall homology with the human and mouse collagen XVIII. Similar to the human and mouse homologue, the chick collagen XVIII mRNA has a size of 4.5 kilobase pairs. In Western blots, collagen XVIII appeared as a smear with a molecular mass of 300 kDa. After treatment with heparitinase, the protein was reduced in molecular mass by 120 kDa to a protein core of 180 kDa. Collagen XVIII has typical features of a collagen, such as its existence, under nondenaturing conditions, as a non-covalently linked oligomer, and a sensitivity of the core protein to collagenase digestion. It also has characteristics of an HSPG, such as long heparitinase-sensitive carbohydrate chains and a highly negative net charge. Collagen XVIII is abundant in basal laminae of the retina, epidermis, pia, cardiac and striated muscle, kidney, blood vessels, and lung. In situ hybridization showed that the main expression of collagen XVIII: HSPG in the chick embryo is in the kidney and the peripheral nervous system. As a substrate, collagen XVIII moderately promoted the adhesion of Schwann cells but had no such activity on peripheral nervous system neurons and axons.