Chaw Ro Crystal, Correa-Garhwal Sandra M, Clarke Thomas H, Ayoub Nadia A, Hayashi Cheryl Y
Department of Biology, University of California , Riverside, California 92521, United States.
Department of Biology, Washington and Lee University , Lexington, Virginia 24450, United States.
J Proteome Res. 2015 Oct 2;14(10):4223-31. doi: 10.1021/acs.jproteome.5b00353. Epub 2015 Sep 1.
Spider silk research has largely focused on spidroins, proteins that are the primary components of spider silk fibers. Although a number of spidroins have been characterized, other types of proteins associated with silk synthesis are virtually unknown. Previous analyses of tissue-specific RNA-seq libraries identified 647 predicted genes that were differentially expressed in silk glands of the Western black widow, Latrodectus hesperus. Only ∼5% of these silk-gland specific transcripts (SSTs) encode spidroins; although the remaining predicted genes presumably encode other proteins associated with silk production, this is mostly unverified. Here, we used proteomic analysis of multiple silk glands and dragline silk fiber to investigate the translation of the differentially expressed genes. We find 48 proteins encoded by the differentially expressed transcripts in L. hesperus major ampullate, minor ampullate, and tubuliform silk glands and detect 17 SST encoded proteins in major ampullate silk fibers. The observed proteins include known silk-related proteins, but most are uncharacterized, with no annotation. These unannotated proteins likely include novel silk-associated proteins. Major and minor ampullate glands have the highest overlap of identified proteins, consistent with their shared, distinctive ampullate shape and the overlapping functions of major and minor ampullate silks. Our study substantiates and prioritizes predictions from differential expression analysis of spider silk gland transcriptomes.
蜘蛛丝研究主要集中在蜘蛛丝蛋白上，这些蛋白是蜘蛛丝纤维的主要成分。尽管已经对多种蜘蛛丝蛋白进行了表征，但与丝合成相关的其他类型蛋白质实际上却鲜为人知。先前对组织特异性RNA测序文库的分析确定了647个预测基因，这些基因在西部黑寡妇（Latrodectus hesperus）的丝腺中差异表达。这些丝腺特异性转录本（SST）中只有约5%编码蜘蛛丝蛋白；尽管其余预测基因可能编码与丝生产相关的其他蛋白质，但这大多未经证实。在这里，我们对多个丝腺和拖牵丝纤维进行了蛋白质组学分析，以研究差异表达基因的翻译情况。我们在西部黑寡妇的主要壶腹状丝腺、次要壶腹状丝腺和管状丝腺中发现了48种由差异表达转录本编码的蛋白质，并在主要壶腹状丝纤维中检测到17种由SST编码的蛋白质。观察到的蛋白质包括已知的与丝相关的蛋白质，但大多数是未表征的，没有注释。这些未注释的蛋白质可能包括新的与丝相关的蛋白质。主要壶腹状丝腺和次要壶腹状丝腺中鉴定出的蛋白质重叠度最高，这与其共同的、独特的壶腹状形状以及主要壶腹状丝和次要壶腹状丝的重叠功能一致。我们的研究证实了蜘蛛丝腺转录组差异表达分析的预测，并对其进行了优先级排序。
