Bhalerao J, Tylzanowski P, Filie J D, Kozak C A, Merregaert J
Department of Biochemistry, University of Antwerp, Belgium.
J Biol Chem. 1995 Jul 7;270(27):16385-94. doi: 10.1074/jbc.270.27.16385.
A novel 85-kDa protein secreted by the mouse stromal osteogenic cell line MN7 was identified using two-dimensional polyacrylamide gel electrophoresis (Mathieu, E., Meheus, L., Raymackers, J., and Merregaert, J. (1994) J. Bone Miner. Res. 9, 903-913). Degenerate primers were used to isolate the cDNA coding for this protein. The full-length cDNA clone is 1.9 kilobases (kb) and codes for a protein of 559 amino acid residues. The DNA and deduced amino acid sequences have no counterparts in public data bases, but a structural similarity involving typical cysteine doublets can be observed to serum albumin family proteins and to Endo16 (a calcium-binding protein of sea urchin). Northern blot analysis revealed the presence of a 1.9-kb transcript in various tissues, and a shorter transcript of 1.5 kb, derived by alternative splicing in tail, front paw and skin of embryonic mice. The gene for the p85 protein, termed Ecm1 (for extracellular matrix protein 1), is a single-copy gene, which was localized to the region on mouse chromosome 3 known to contain at least one locus associated with developmental disorders of the skin, soft coat (soc). Alternative splicing may serve as a mechanism for generating functional diversity in the Ecm1 gene.
利用二维聚丙烯酰胺凝胶电泳法鉴定出一种由小鼠基质成骨细胞系MN7分泌的新型85 kDa蛋白（Mathieu, E., Meheus, L., Raymackers, J., and Merregaert, J. (1994) J. Bone Miner. Res. 9, 903 - 913）。使用简并引物分离编码该蛋白的cDNA。全长cDNA克隆为1.9千碱基（kb），编码一个由559个氨基酸残基组成的蛋白。DNA和推导的氨基酸序列在公共数据库中没有对应物，但可以观察到与血清白蛋白家族蛋白和Endo16（海胆的一种钙结合蛋白）存在涉及典型半胱氨酸双联体的结构相似性。Northern印迹分析显示在各种组织中存在一个1.9 kb的转录本，以及在胚胎小鼠的尾巴、前爪和皮肤中通过可变剪接产生的一个1.5 kb的较短转录本。编码p85蛋白的基因称为Ecm1（细胞外基质蛋白1），是一个单拷贝基因，定位于小鼠3号染色体上已知包含至少一个与皮肤发育障碍、软毛（soc）相关的位点的区域。可变剪接可能是Ecm1基因产生功能多样性的一种机制。
