Banyard Jacqueline, Bao Lere, Zetter Bruce R
Program in Vascular Biology and Department of Surgery, Children's Hospital/Harvard Medical School, Boston, Massachusetts 02115, USA.
J Biol Chem. 2003 Jun 6;278(23):20989-94. doi: 10.1074/jbc.M210616200. Epub 2003 Mar 18.
We have identified a transmembrane collagen, collagen XXIII, in rat prostate carcinoma cells. Differential display of mRNA expression in prostate carcinoma sublines with varying metastatic potential revealed overexpression of this transcript in the metastatic AT6.1 subline. cDNA cloning identified a 2733-bp transcript from AT6.1 RNA, encoding a protein of 532 amino acids, together with a 3067-bp human homologue, resulting in a 540-amino acid protein. Collagen XXIII is predicted to be a type II membrane protein consisting of an amino-terminal cytoplasmic domain, a transmembrane region, and three collagenous domains flanked by short noncollagenous domains. Collagen XXIII is a new member of the transmembrane collagen family, showing structural homology with the transmembrane collagens XIII and XXV. We present evidence that collagen XXIII is expressed as a approximately 75-kDa protein at the cell surface and that it can be cleaved by furin protease activity. Cleavage results in a approximately 60-kDa soluble protein that forms a multimeric complex and exhibits a low affinity interaction with heparin.
我们在大鼠前列腺癌细胞中鉴定出一种跨膜胶原蛋白——胶原蛋白XXIII。对具有不同转移潜能的前列腺癌亚系中mRNA表达的差异显示表明，该转录本在转移性AT6.1亚系中过表达。cDNA克隆从AT6.1 RNA中鉴定出一个2733 bp的转录本，编码一个532个氨基酸的蛋白质，同时还有一个3067 bp的人类同源物，产生一个540个氨基酸的蛋白质。胶原蛋白XXIII预计是一种II型膜蛋白，由一个氨基末端胞质结构域、一个跨膜区域和三个由短的非胶原结构域侧翼的胶原结构域组成。胶原蛋白XXIII是跨膜胶原蛋白家族的新成员，与跨膜胶原蛋白XIII和XXV具有结构同源性。我们提供的证据表明，胶原蛋白XXIII在细胞表面以约75 kDa的蛋白质形式表达，并且它可以被弗林蛋白酶活性切割。切割产生一个约60 kDa的可溶性蛋白质，该蛋白质形成多聚体复合物并与肝素表现出低亲和力相互作用。
