MacKrell A J, Blumberg B, Haynes S R, Fessler J H
Molecular Biology Institute, University of California, Los Angeles 90024.
Proc Natl Acad Sci U S A. 1988 Apr;85(8):2633-7. doi: 10.1073/pnas.85.8.2633.
A mutant of Drosophila melanogaster carrying the lethal(1) myospheroid mutation [l(1)mys] has a defective musculature and a phenotype that suggests a defect of basement membranes. The genomic region that is interrupted by an insertion in a mutant carrying l(1)mys was used to isolate cDNA clones, and their sequences are presented here. The cDNA sequence predicts a cysteine-rich integral membrane protein that displays 45% sequence identity to chicken integrin and the human fibronectin receptor beta subunit and much greater similarity over localized segments. These similarities extend to other vertebrate integrin beta subunits, and we conclude that the myospheroid protein is an integrin beta subunit of Drosophila. This implies evolutionary conservation of a group of transmembrane proteins that are receptors for extracellular matrix and, coupled with the myospheroid phenotype, indicates an important role for the interaction of cells with extracellular matrix during development.
携带致死（1）肌球样突变 [l(1)mys] 的黑腹果蝇突变体具有肌肉组织缺陷，其表型提示基底膜存在缺陷。在携带 l(1)mys 的突变体中，因插入而中断的基因组区域被用于分离 cDNA 克隆，本文展示了它们的序列。该 cDNA 序列预测出一种富含半胱氨酸的整合膜蛋白，它与鸡整合素和人纤连蛋白受体β亚基具有 45% 的序列同一性，并且在局部片段上具有更高的相似性。这些相似性延伸至其他脊椎动物整合素β亚基，我们得出结论，肌球样蛋白是果蝇的一种整合素β亚基。这意味着一组作为细胞外基质受体的跨膜蛋白在进化上具有保守性，并且结合肌球样表型表明细胞与细胞外基质的相互作用在发育过程中具有重要作用。
