TY  - JOUR
A1  - Schwede, Angela
A1  - Jones, Nicola
A1  - Engstler, Markus
A1  - Carrington, Mark
T1  - The VSG C-terminal domain is inaccessible to antibodies on live trypanosomes
JF  - Molecular & Biochemical Parasitology
N2  - In the mammalian host, the Trypanosoma brucei cell surface is covered with a densely packed protein coat of a single protein, the variant surface glycoprotein (VSG). The VSG is believed to shield invariant surface proteins from host antibodies but there is limited information on how far antibodies can penetrate into the VSG monolayer. Here, the VSG surface coat was probed to determine whether it acts as a barrier to binding of antibodies to the membrane proximal VSG C-terminal domain. The binding of C-terminal domain antibodies to VSG221 or VSG118 was compared with antibodies recognising the cognate whole VSGs. The C-terminal VSG domain was inaccessible to antibodies on live cells but not on fixed cells. This provides further evidence that the VSG coat acts as a barrier and protects the cell from antibodies that would otherwise bind to some of the other externally disposed proteins.
KW  - Trypanosome
KW  - VSG
KW  - Trypanosoma brucei
KW  - Cell surface
KW  - Antibody
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-142746
VL  - 175
IS  - 2
ER  - 
TY  - JOUR
A1  - Kramer, Susanne
A1  - Piper, Sophie
A1  - Estevez, Antonio
A1  - Carrington, Mark
T1  - Polycistronic trypanosome mRNAs are a target for the exosome
JF  - Molecular and Biochemical Parasitology
N2  - Eukaryotic cells have several mRNA quality control checkpoints to avoid the production of aberrant proteins. Intron-containing mRNAs are actively degraded by the nuclear exosome, prevented from nuclear exit and, if these systems fail, degraded by the cytoplasmic NMD machinery. Trypanosomes have only two introns. However, they process mRNA5 from long polycistronic precursors by trans-splicing and polycistronic mRNA molecules frequently arise from any missed splice site. Here, we show that RNAi depletion of the trypanosome exosome, but not of the cytoplasmic 5'-3' exoribonuclease XRNA or the NMD helicase UPF1, causes accumulation of oligocistronic mRNA5. We have also revisited the localization of the trypanosome exosome by expressing eYFP-fusion proteins of the exosome subunits RRP44 and RRP6. Both proteins are significantly enriched in the nucleus. Together with published data, our data suggest a major nuclear function of the trypanosome exosome in rRNA, snoRNA and mRNA quality control.
KW  - Trypanosoma brucei
KW  - Exosome
KW  - NMD
KW  - Polycistronic mRNA
KW  - trans-splicing
KW  - Trypanosomes
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191350
VL  - 205
IS  - 1-2
ER  -