Alternatively spliced forms of the Drosophila alphaPS2 subunit of integrin are sufficient for viability and can replace the function of the alphaPS1 subunit of integrin in the retina.
Alternatively spliced forms of the Drosophila alphaPS2 subunit of integrin are sufficient for viability and can replace the function of the alphaPS1 subunit of integrin in the retina.
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作者：
C. Roote;S. Zusman
果蝇膨胀（if）基因编码整合素PS家族的alphaPS 2亚基。如果转录本被剪接，使得alphaPS 2以两种替代形式存在，alphaPS 2（C）和alphaPS 2（m8），其在显示影响阳离子需求和配体特异性的区域中相差25个氨基酸残基。在这项研究中，我们研究的功能意义的蛋白质异构体的，如果通过分析能力的转基因生产只有一个异构体，以挽救与PS2整合素的完全丧失相关的发育异常。我们发现，任何一种形式的alphaPS 2都足以拯救if-动物存活;然而，alphaPS 2（C）形式促进生物体的更高存活率。此外，这些研究表明alphaPS 2（C）和alphaPS 2（m8）在发育过程中的不同作用。当在发育中的翅中表达时，alphaPS 2（m8）比alphaPS 2（C）更有效地挽救翅疱表型。眼内alphaPS 2（C）的表达导致感光细胞组织的显性破坏。我们还研究了alphaPS 2和alphaPS 1在果蝇视网膜中维持光感受器组织的能力。切片眼的克隆分析表明需要alphaPS 1，但不需要alphaPS 2。然而，if（m8）或if（C）的异位表达表明，α PS 2的任一剪接形式都可以在功能上取代α PS 1并挽救新眼表型。
The Drosophila inflated (if) gene encodes the alphaPS2 subunit of the PS family of integrins. The if transcript is spliced such that alphaPS2 is found in two alternative forms, alphaPS2(C) and alphaPS2(m8), which differ by 25 amino acid residues in a region shown to affect cation requirements and ligand specificity. In this study, we examine the functional significance of the protein isoforms of if by analyzing the ability of transgenes producing only one isoform to rescue developmental abnormalities associated with complete loss of PS2 integrin. We find that either form of alphaPS2 is sufficient to rescue if- animals to viability; however, the alphaPS2(C) form promotes higher survival of the organism. Furthermore, these studies suggest distinct roles for alphaPS2(C) and alphaPS2(m8) during development. When expressed in the developing wing, alphaPS2(m8) is more efficient at rescuing the if wing blister phenotype than is alphaPS2(C). Expression of alphaPS2(C) in the eye produces dominant disruption of photoreceptor organization. We have also examined the ability of alphaPS2 and alphaPS1 to maintain photoreceptor organization in the Drosophila retina. Clonal analysis of sectioned eyes suggests a requirement for alphaPS1, but not alphaPS2. However, ectopic expression of if(m8) or if(C) shows that either splice form Of alphaPS2 can functionally replace alphaPS1 and rescue the mew eye phenotype.