Francischetti Ivo M B, My Pham Van, Mans Ben J, Andersen John F, Mather Thomas N, Lane Robert S, Ribeiro José M C
Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20892-8132, USA.
Insect Biochem Mol Biol. 2005 Oct;35(10):1142-61. doi: 10.1016/j.ibmb.2005.05.007.
Sequencing of an Ixodes pacificus salivary gland cDNA library yielded 1068 sequences with an average undetermined nucleotide of 1.9% and an average length of 487 base pairs. Assembly of the expressed sequence tags yielded 557 contigs, 138 of which appear to code for secreted peptides or proteins based on translation of a putative signal peptide. Based on the BLASTX similarity of these contigs to 66 matches of Ixodes scapularis peptide sequences, only 58% sequence identity was found, indicating a rapid divergence of salivary proteins as observed previously for mosquito and triatomine bug salivary proteins. Here we report 106 mostly full-length sequences that clustered in 16 different families: Basic-tail proteins rich in lysine in the carboxy-terminal, Kunitz-containing proteins (monolaris, ixolaris and penthalaris families), proline-rich peptides, 5-, 9.4- and 18.7-kDa proteins of unknown functions, in addition to metalloproteases (class PIII-like) similar to reprolysins. We also have found a family of disintegrins, named ixodegrins that display homology to variabilin, a GPIIb/IIIa antagonist from the tick Dermacentor variabilis. In addition, we describe peptides (here named ixostatins) that display remarkable similarities to the cysteine-rich domain of ADAMST-4 (aggrecanase). Many molecules were assigned in the lipocalin family (histamine-binding proteins); others appear to be involved in oxidant metabolism, and still others were similar to ixodid proteins such as the anticomplement ISAC. We also identified for the first time a neuropeptide-like protein (nlp-31) with GGY repeats that may have antimicrobial activity. In addition, 16 novel proteins without significant similarities to other tick proteins and 37 housekeeping proteins that may be useful for phylogenetic studies are described. Some of these proteins may be useful for studying vascular biology or the immune system, for vaccine development, or as immunoreagents to detect prior exposure to ticks. Electronic version of the manuscript can be found at.
对太平洋硬蜱唾液腺cDNA文库进行测序，得到1068个序列，平均未确定核苷酸比例为1.9%，平均长度为487个碱基对。对表达序列标签进行组装，得到557个重叠群，其中138个基于推定信号肽的翻译似乎编码分泌肽或蛋白质。基于这些重叠群与肩突硬蜱肽序列的66个匹配的BLASTX相似性，仅发现58%的序列同一性，表明唾液蛋白快速分化，这与先前在蚊子和锥蝽唾液蛋白中观察到的情况一致。在此，我们报告了106个大多为全长的序列，它们聚集成16个不同的家族：羧基末端富含赖氨酸的碱性尾蛋白、含库尼茨结构域的蛋白（单olaris、ixolaris和penthalaris家族）、富含脯氨酸的肽、功能未知的5 kDa、9.4 kDa和18.7 kDa蛋白，此外还有与解聚素相似的金属蛋白酶（类PIII样）。我们还发现了一个去整合素家族，命名为ixodegrins，它们与变异素具有同源性，变异素是一种来自变异革蜱的GPIIb/IIIa拮抗剂。此外，我们描述了与ADAMST - 4（聚集蛋白聚糖酶）富含半胱氨酸结构域具有显著相似性的肽（此处命名为ixostatins）。许多分子被归类于脂质运载蛋白家族（组胺结合蛋白）；其他分子似乎参与氧化代谢，还有一些与硬蜱蛋白如抗补体ISAC相似。我们还首次鉴定了一种具有GGY重复序列且可能具有抗菌活性的神经肽样蛋白（nlp - 31）。此外，还描述了16种与其他蜱蛋白无显著相似性的新蛋白以及37种可能对系统发育研究有用的管家蛋白。其中一些蛋白可能对研究血管生物学或免疫系统、疫苗开发或作为检测先前是否接触过蜱的免疫试剂有用。手稿的电子版可在……找到。
