Adhesion of outer membrane proteins containing tandem repeats of Anaplasma and Ehrlichia species (Rickettsiales: Anaplasmataceae) to tick cells
Adhesion of outer membrane proteins containing tandem repeats of Anaplasma and Ehrlichia species (Rickettsiales: Anaplasmataceae) to tick cells
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DOI：
10.1016/j.vetmic.2003.11.001
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发表时间：
2004-03-05
影响因子：
3.3
通讯作者：
Kocan, KM
中科院分区：
文献类型：
--
作者：
de la Fuente, J;Garcia-Garcia, JC;Kocan, KM
壁虱传播的立克次体对细胞的感染似乎是由外膜蛋白介导的，外膜蛋白允许病原体附着在宿主细胞上。边缘无浆虫的主要表面蛋白(MSP)1a是硬蜱细胞的粘附素，是无浆体属的模式种。边缘疟原虫MSP1a具有数量可变的串联28或29个氨基酸重复序列，位于蛋白质的氨基末端区域，该区域包含黏附结构域，这是感染蜱细胞所必需的，也是足够的。MSP1a的研究证明了将结构和功能特征结合起来对粘附性蛋白鉴定的重要性。在本研究中，从无浆体科生物中选择了其他含有串联重复序列的外膜蛋白，并研究了它们与扁虱细胞的粘附性。然后对粘附性和蛋白质特性进行分析，以提供从基因组序列中识别的蛋白质的粘附性的预测指标。所选择的蛋白包括边际嗜血杆菌MSP1a、吞噬细胞性嗜血杆菌100和130 kDa、查菲埃利希菌120 kDa、犬埃希氏菌140 kDa和瘤胃埃希氏菌“粘蛋白”。在所研究的蛋白质中，边缘毛滴虫的MSP1a和反转录病毒的粘蛋白“粘蛋白”被发现是壁虱细胞的粘附素。虽然所有这些重组外膜蛋白都是糖基化的，但边缘农杆菌MSP1a和瘤胃肠粘蛋白“粘蛋白”有一个共同的特征，即在串联重复序列中具有较高的Ser/Thr含量。本文报道的结果提供了有关瘤胃肠粘蛋白作为扁虱细胞粘附素的作用的新信息，也提示了多聚糖在粘附素分子中的作用。(C)2003爱思唯尔B.V.保留所有权利。
Infection of cells by tick-borne rickettsiae appears to be mediated by outer membrane proteins that allow pathogens to adhere to host cells. Major surface protein (MSP) 1a of Anaplasma marginale, the type species for the genus Anaplasma, was shown previously to be an adhesin for tick cells. The A. marginale MSP1a has a variable number of tandem 28 or 29 amino acid repeats located in the amino terminal region of the protein that contains an adhesion domain that is necessary and sufficient for infection of tick cells. The MSP1a studies demonstrated the importance of combining structural and functional characteristics for identification of adhesive proteins. In the present study other outer membrane proteins containing tandem repeats were selected from organisms of the family Anaplasmataceae and studied for their adhesive properties to tick cells. The adhesive properties and protein characteristics were then analyzed in order to provide a predictor of the adhesion function of proteins identified from genome sequences. Proteins selected included the A. marginale MSP1a, A. phagocytophilum 100 and 130 kDa, Ehrlichia chaffeensis 120 kDa, E canis 140 kDa and E. ruminantium "mucin", which were all cloned and expressed in Escherichia coli and then tested as adhesins for cultured IDE8 cells. Of the proteins studied, the A. marginale MSP1a and the E. ruminantium "mucin" were found to be adhesins for tick cells. Although all of these recombinant outer membrane proteins were glycosylated, the A. marginale MSP1a and E. ruminantium "mucin" adhesins shared a common feature of having a high Ser/Thr content in the tandem repeats. The results reported herein provide new information on the role of E. ruminantium "mucin" as an adhesin for tick cells and also suggest a role of glycans in adhesin molecules. (C) 2003 Elsevier B.V. All rights reserved.