Open AccessEndosomal Localization of the Serum Resistance-Associated Protein in African Trypanosomes Confers Human Infectivity
Author(s) -
Natalie Stephens,
Stephen L. Hajduk
Publication year - 2011
Publication title -
eukaryotic cell
Language(s) - English
Resource type - Journals
eISSN - 1535-9778
pISSN - 1535-9786
DOI - 10.1128/ec.05112-11
Subject(s) - infectivity , biology , endosome , trypanosoma brucei , microbiology and biotechnology , virology , gene , genetics , virus , intracellular
Trypanosoma brucei rhodesiense is the causative agent of human African sleeping sickness. While the closely related subspeciesT. brucei brucei is highly susceptible to lysis by a subclass of human high-density lipoproteins (HDL) called trypanosome lytic factor (TLF),T. brucei rhodesiense is resistant and therefore able to establish acute and fatal infections in humans. This resistance is due to expression of the serum resistance-associated (SRA) gene, a member of the variant surface glycoprotein (VSG) gene family. Although much has been done to establish the role of SRA in human serum resistance, the specific molecular mechanism of SRA-mediated resistance remains a mystery. Thus, we report the trafficking and steady-state localization of SRA in order to provide more insight into the mechanism of SRA-mediated resistance. We show that SRA traffics to the flagellar pocket of bloodstream-formT. brucei organisms, where it localizes transiently before being endocytosed to its steady-state localization in endosomes, and we demonstrate that the critical point of colocalization between SRA and TLF occurs intracellularly.