Complete amino acid sequence of a novel integrin beta subunit (beta 6) identified in epithelial cells using the polymerase chain reaction.
Complete amino acid sequence of a novel integrin beta subunit (beta 6) identified in epithelial cells using the polymerase chain reaction.
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DOI：
10.1016/s0021-9258(19)38425-x
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发表时间：
1990-07
期刊：
影响因子：
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通讯作者：
D. Sheppard;C. Rozzo;L. Starr;V. Quaranta;D. Erle;R. Pytela
中科院分区：
文献类型：
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作者：
D. Sheppard;C. Rozzo;L. Starr;V. Quaranta;D. Erle;R. Pytela
粘附受体的整联蛋白家族由几种异二聚体糖蛋白组成，每种糖蛋白由一个α亚基和一个β亚基组成。三种不同的哺乳动物β亚基，β 1，β 2和β 3，已经被测序，但最近的证据表明存在其他几种亚基。扩增豚鼠气道上皮细胞cDNA的寡核苷酸引物设计识别共识整合素β亚基序列导致一种新的部分cDNA序列的鉴定。含有该序列的部分的克隆用于筛选从人胰腺癌细胞系FG-2构建的cDNA文库，并鉴定了编码该蛋白的人同源物的全长序列的一系列重叠克隆。该788个氨基酸的序列分别与β 1、β 2和β 3的序列具有43%、38%和47%的同一性。这种新型蛋白质和先前测序的β亚基之间共享的特征包括细胞外结构域中所有56个半胱氨酸残基的位置、单一推定跨膜结构域和短推定胞质结构域。然而，一个独特的11个氨基酸的延伸在羧基末端，不存在于任何其他β亚基，是与细胞质成分的独特的相互作用的暗示。人类和豚鼠序列的比较揭示了高度（94%）的跨物种保护。因为这种蛋白质与最近描述的另外两种整合素β 4和β 5明显不同，我们建议将其命名为β 6。
The integrin family of adhesion receptors consists of several heterodimeric glycoproteins, each composed of one alpha and one beta subunit. Three different mammalian beta subunits, beta 1, beta 2, and beta 3, have been sequenced, but recent evidence suggests the existence of several others. Amplification of guinea pig airway epithelial cell cDNA with oligonucleotide primers designed to recognize consensus integrin beta subunit sequences led to the identification of a novel partial cDNA sequence. Clones containing portions of this sequence were used to screen cDNA libraries constructed from the human pancreatic carcinoma cell line FG-2 and identified a series of overlapping clones encoding the full-length sequence of the human homologue of this protein. This sequence of 788 amino acids is 43, 38, and 47% identical to the sequences of beta 1, beta 2, and beta 3, respectively. Features shared between this novel protein and the previously sequenced beta subunits include the positions of all 56 cysteine residues in the extracellular domain, the single putative transmembrane domain, and the short putative cytoplasmic domain. However, a unique 11-amino acid extension at the carboxyl terminus, not present in any of the other beta subunits, is suggestive of distinctive interactions with cytoplasmic components. Comparison of the human and guinea pig sequences reveals a high degree (94%) of cross-species conservation. Because this protein is clearly distinct from the two other recently described integrins beta 4 and beta 5, we propose to designate it beta 6.