Wolffe E J, Gause W C, Pelfrey C M, Holland S M, Steinberg A D, August J T
Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
J Biol Chem. 1990 Jan 5;265(1):341-7.
We describe the isolation and sequencing of a cDNA encoding mouse Pgp-1. An oligonucleotide probe corresponding to the NH2-terminal sequence of the purified protein was synthesized by the polymerase chain reaction and used to screen a mouse macrophage lambda gt11 library. A cDNA clone with an insert of 1.2 kilobases was selected and sequenced. In Northern blot analysis, only cells expressing Pgp-1 contained mRNA species that hybridized with this Pgp-1 cDNA. The nucleotide sequence of the cDNA has a single open reading frame that yields a protein-coding sequence of 1076 base pairs followed by a 132-base pair 3'-untranslated sequence that includes a putative polyadenylation signal but no poly(A) tail. The translated sequence comprises a 13-amino acid signal peptide followed by a polypeptide core of 345 residues corresponding to an Mr of 37,800. Portions of the deduced amino acid sequence were identical to those obtained by amino acid sequence analysis from the purified glycoprotein, confirming that the cDNA encodes Pgp-1. The predicted structure of Pgp-1 includes an NH2-terminal extracellular domain (residues 14-265), a transmembrane domain (residues 266-286), and a cytoplasmic tail (residues 287-358). Portions of the mouse Pgp-1 sequence are highly similar to that of the human CD44 cell surface glycoprotein implicated in cell adhesion. The protein also shows sequence similarity to the proteoglycan tandem repeat sequences found in cartilage link protein and cartilage proteoglycan core protein which are thought to be involved in binding to hyaluronic acid.
我们描述了编码小鼠Pgp-1的cDNA的分离和测序。通过聚合酶链反应合成了与纯化蛋白的NH2末端序列相对应的寡核苷酸探针，并用于筛选小鼠巨噬细胞λgt11文库。选择了一个插入片段为1.2千碱基的cDNA克隆并进行测序。在Northern印迹分析中，只有表达Pgp-1的细胞含有与该Pgp-1 cDNA杂交的mRNA种类。该cDNA的核苷酸序列有一个单一的开放阅读框，产生一个1076个碱基对的蛋白质编码序列，随后是一个132个碱基对的3'-非翻译序列，其中包括一个推定的聚腺苷酸化信号，但没有聚(A)尾。翻译后的序列包括一个13个氨基酸的信号肽，后面是一个345个残基的多肽核心段，对应的分子量为37,800。推导的氨基酸序列的部分与从纯化的糖蛋白进行氨基酸序列分析得到的序列相同，证实该cDNA编码Pgp-1。预测的Pgp-1结构包括一个NH2末端细胞外结构域（第14-265位残基）、一个跨膜结构域（第266-286位残基）和一个细胞质尾（第287-358位残基）。小鼠Pgp-1序列的部分与参与细胞粘附的人CD44细胞表面糖蛋白的序列高度相似。该蛋白还显示出与软骨连接蛋白和软骨蛋白聚糖核心蛋白中发现的蛋白聚糖串联重复序列的序列相似性，这些序列被认为参与与透明质酸的结合。
