title: Post-translational import of protein into the endoplasmic reticulum of a trypanosome: an in vitro system for discovery of anti-trypanosomal chemical entities.
abstract: HAT (human African trypanosomiasis), caused by the protozoan parasite Trypanosoma brucei, is an emerging disease for which new drugs are needed. Expression of plasma membrane proteins [e.g. VSG (variant surface glycoprotein)] is crucial for the establishment and maintenance of an infection by T. brucei. Transport of a majority of proteins to the plasma membrane involves their translocation into the ER (endoplasmic reticulum). Thus inhibition of protein import into the ER of T. brucei would be a logical target for discovery of lead compounds against trypanosomes. We have developed a TbRM (T. brucei microsome) system that imports VSG_117 post-translationally. Using this system, MAL3-101, equisetin and CJ-21,058 were discovered to be small molecule inhibitors of VSG_117 translocation into the ER. These agents also killed bloodstream T. brucei in vitro; the concentrations at which 50% of parasites were killed (IC50) were 1.5 microM (MAL3-101), 3.3 microM (equisetin) and 7 microM (CJ-21,058). Thus VSG_117 import into TbRMs is a rapid and novel assay to identify 'new chemical entities' (e.g. MAL3-101, equisetin and CJ-21,058) for anti-trypanosome drug development.
authors.affiliation: Department of Cellular Biology, University of Georgia, 724 Biological Sciences Building, Athens, GA 30602, USA.
authors.forename: Bhargavi
authors.initials: B
authors.lastname: Patham
authors.forename: Josh
authors.initials: J
authors.lastname: Duffy
authors.forename: Ariel
authors.initials: A
authors.lastname: Lane
authors.forename: Richard C
authors.initials: RC
authors.lastname: Davis
authors.forename: Peter
authors.initials: P
authors.lastname: Wipf
authors.forename: Sheara W
authors.initials: SW
authors.lastname: Fewell
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Brodsky
authors.forename: Kojo
authors.initials: K
authors.lastname: Mensa-Wilmot
mesh_terms: D000818:Animals; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D009281:Naphthalenes / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D014346:Trypanosoma brucei brucei / Q000378:metabolism*; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000235:genetics / Q000378:metabolism*
chemical_list: C451492:CJ 21058; D009281:Naphthalenes; D011760:Pyrrolidinones; D013764:Tetrahydronaphthalenes; D014643:Variant Surface Glycoproteins, Trypanosoma; C024509:equisetin