de Miguel N, Echeverria P C, Angel S O
Laboratorio de Parasitología Molecular, IIB-INTECH, Camino Circunvalación Laguna Km6, C.C 164, 7130 Chascomús, Prov. Buenos Aires, Argentina.
Eukaryot Cell. 2005 Dec;4(12):1990-7. doi: 10.1128/EC.4.12.1990-1997.2005.
The results of this study describe the identification and characterization of the Toxoplasma gondii alpha-crystallin/small heat shock protein (sHsp) family. By database (www.toxodb.org) search, five parasite sHsps (Hsp20, Hsp21, Hsp28, Hsp29, and the previously characterized Hsp30/Bag1) were identified. As expected, they share the homologous alpha-crystallin domain, which is the key characteristic of sHsps. However, the N-terminal segment of each protein contains unique characteristics in size and sequence. Most T. gondii sHsps are constitutively expressed in tachyzoites and fully differentiated bradyzoites, with the exception of Hsp30/Bag1. Interestingly, by subcellular localization we observed that T. gondii sHsps are located in different compartments. Hsp20 is located at the apical end of the cell, Hsp28 is located inside the mitochondrion, Hsp29 showed a membrane-associated labeling, and Hsp21 appeared throughout the cytosol of the parasites. These particular differences in the immunostaining patterns suggest that their targets and functions might be different.
本研究结果描述了刚地弓形虫α-晶状体蛋白/小热休克蛋白（sHsp）家族的鉴定与特征。通过数据库（www.toxodb.org）搜索，鉴定出五种寄生虫sHsp（Hsp20、Hsp21、Hsp28、Hsp29以及先前已鉴定的Hsp30/Bag1）。正如预期的那样，它们共享同源的α-晶状体蛋白结构域，这是sHsp的关键特征。然而，每种蛋白质的N端片段在大小和序列上具有独特特征。除Hsp30/Bag1外，大多数刚地弓形虫sHsp在速殖子和完全分化的缓殖子中组成性表达。有趣的是，通过亚细胞定位我们观察到刚地弓形虫sHsp位于不同的区室。Hsp20位于细胞顶端，Hsp28位于线粒体内，Hsp29显示出与膜相关的标记，而Hsp21出现在寄生虫的整个细胞质中。这些免疫染色模式的特定差异表明它们的靶标和功能可能不同。
