Post-translational import of protein into the endoplasmic reticulum of a trypanosome: an in vitro system for discovery of anti-trypanosomal chemical entities.
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.
Patham
Bhargavi
B
Department of Cellular Biology, University of Georgia, 724 Biological Sciences Building, Athens, GA 30602, USA.
Duffy
Josh
J
Lane
Ariel
A
Davis
Richard C
RC
Wipf
Peter
P
Fewell
Sheara W
SW
Brodsky
Jeffrey L
JL
Mensa-Wilmot
Kojo
K
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*
C451492:CJ 21058; D009281:Naphthalenes; D011760:Pyrrolidinones; D013764:Tetrahydronaphthalenes; D014643:Variant Surface Glycoproteins, Trypanosoma; C024509:equisetin