Trypanosomatid RACK1 orthologs show functional differences associated with translation despite similar roles in Leishmania pathogenesis.
Trypanosomatid RACK1 orthologs show functional differences associated with translation despite similar roles in Leishmania pathogenesis.
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DOI：
10.1371/journal.pone.0020710
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Kelly BL
中科院分区：
文献类型：
--
作者：
Choudhury K;Cardenas D;Pullikuth AK;Catling AD;Aiyar A;Kelly BL
RACK1 蛋白属于真核生物 WD40 重复蛋白家族，作为多种细胞事件的空间调节因子，包括信号传导途径、细胞周期和翻译。对于后一种作用，结构和遗传学研究表明，RACK1 通过其第一个 WD40 结构域中的两个保守的带正电荷的氨基酸与核糖体结合。与 RACK1 不同，包括布氏锥虫 RACK1 (TbRACK1)，这两个带正电荷的残基中只有一个在利什曼原虫主要 RACK1 直系同源物 LACK 的第一个 WD40 结构域中保守。我们比较了毒力减弱的LACK单拷贝（LACK/-）L.major，与表达两个LACK拷贝（LACK/LACK）或LACK和TbRACK1各一个拷贝（LACK/TbRACK1）的L.major，以评估这些结构上不同的RACK1直向同源物在翻译、宿主温度下的活力和发病机制方面的功能。我们的结果表明，尽管核糖体结合残基在 LACK 中并不完全保守，但 LACK 和 TbRACK1 分别与 LACK/LACK 和 LACK/TbRACK1 L. Major 中的单核糖体和多核糖体共沉淀。 LACK/LACK 和 LACK/TbRACK1 菌株对翻译抑制剂的敏感性不同，这意味着 RACK1 蛋白之间的微小序列差异可以改变它们的功能特性。虽然在生化上有区别，但与 LACK/- 寄生虫相比，LACK/LACK 和 LACK/TbRACK1 系都更能耐受高温，对翻译抑制剂具有抵抗力，并且在体内表现出强大的发病机制。
RACK1 proteins belong to the eukaryote WD40-repeat protein family and function as spatial regulators of multiple cellular events, including signaling pathways, the cell cycle and translation. For this latter role, structural and genetic studies indicate that RACK1 associates with the ribosome through two conserved positively charged amino acids in its first WD40 domain. Unlike RACK1s, including Trypanosoma brucei RACK1 (TbRACK1), only one of these two positively-charged residues is conserved in the first WD40 domain of the Leishmania major RACK1 ortholog, LACK. We compared virulence-attenuated LACK single copy (LACK/-) L. major, with L. major expressing either two LACK copies (LACK/LACK), or one copy each of LACK and TbRACK1 (LACK/TbRACK1), to evaluate the function of these structurally distinct RACK1 orthologs with respect to translation, viability at host temperatures and pathogenesis. Our results indicate that although the ribosome-binding residues are not fully conserved in LACK, both LACK and TbRACK1 co-sedimented with monosomes and polysomes in LACK/LACK and LACK/TbRACK1 L. major, respectively. LACK/LACK and LACK/TbRACK1 strains differed in their sensitivity to translation inhibitors implying that minor sequence differences between the RACK1 proteins can alter their functional properties. While biochemically distinguishable, both LACK/LACK and LACK/TbRACK1 lines were more tolerant of elevated temperatures, resistant to translation inhibitors, and displayed robust pathogenesis in vivo, contrasting to LACK/- parasites.
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影响因子：
4.8
作者：
Le, H;Browning, KS;Gallie, DR
通讯作者：
Gallie, DR
DOI：
10.1084/jem.20031162
发表时间：
2003-12-01
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Kelly BL;Stetson DB;Locksley RM
通讯作者：
Locksley RM
影响因子：
8
作者：
Chang, BY;Harte, RA;Cartwright, CA
通讯作者：
Cartwright, CA
影响因子：
1.5
作者：
Leifso, Kirk;Cohen-Freue, Gabriela;McMaster, W. Robert
通讯作者：
McMaster, W. Robert
DOI：
10.1073/pnas.0500926102
发表时间：
2005-07-19
影响因子：
11.1
作者：
Gao, HX;Ayub, MJ;Frank, J
通讯作者：
Frank, J