TITLE

Blocking Variant Surface Glycoprotein Synthesis in Trypanosoma brucei Triggers a General Arrest in Translation Initiation

AUTHOR(S)
Smith, Terry K.; Vasileva, Nadina; Gluenz, Eva; Terry, Stephen; Portman, Neil; Kramer, Susanne; Carrington, Mark; Michaeli, Shulamit; Gull, Keith; Rudenko, Gloria
PUB. DATE
October 2009
SOURCE
PLoS ONE;2009, Vol. 4 Issue 10, p1
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Background: The African trypanosome Trypanosoma brucei is covered with a dense layer of Variant Surface Glycoprotein (VSG), which protects it from lysis by host complement via the alternative pathway in the mammalian bloodstream. Blocking VSG synthesis by the induction of VSG RNAi triggers an unusually precise precytokinesis cell-cycle arrest. Methodology/Principal Findings: Here, we characterise the cells arrested after the induction of VSG RNAi. We were able to rescue the VSG221 RNAi induced cell-cycle arrest through expression of a second different VSG (VSG117 which is not recognised by the VSG221 RNAi) from the VSG221 expression site. Metabolic labeling of the arrested cells showed that blocking VSG synthesis triggered a global translation arrest, with total protein synthesis reduced to less than 1-4% normal levels within 24 hours of induction of VSG RNAi. Analysis by electron microscopy showed that the translation arrest was coupled with rapid disassociation of ribosomes from the endoplasmic reticulum. Polysome analysis showed a drastic decrease in polysomes in the arrested cells. No major changes were found in levels of transcription, total RNA transcript levels or global amino acid concentrations in the arrested cells. Conclusions: The cell-cycle arrest phenotype triggered by the induction of VSG221 RNAi is not caused by siRNA toxicity, as this arrest can be alleviated if a second different VSG is inserted downstream of the active VSG221 expression site promoter. Analysis of polysomes in the stalled cells showed that the translation arrest is mediated at the level of translation initiation rather than elongation. The cell-cycle arrest induced in the presence of a VSG synthesis block is reversible, suggesting that VSG synthesis and/or trafficking to the cell surface could be monitored during the cell-cycle as part of a specific cell-cycle checkpoint.
ACCESSION #
58515436

 

Related Articles

  • Variant Surface Glycoprotein gene repertoires in Trypanosoma brucei have diverged to become strain-specific. Hutchinson, O Clyde; Picozzi, Kim; Jones, Nicola G; Mott, Helen; Sharma, Reuben; Welburn, Susan C; Carrington, Mark // BMC Genomics;2007, Vol. 8, p1 

    Background: In a mammalian host, the cell surface of African trypanosomes is protected by a monolayer of a single variant surface glycoprotein (VSG). The VSG is central to antigenic variation; one VSG gene is expressed at any one time and there is a low frequency stochastic switch to expression...

  • Evolutionary analysis of SEC23A Gene and homology modeling in Zebrafish. Sukhwal, Anshul; Lulu, S. Sajitha; Vino, S.; Dilshad, Jaigam // Drug Invention Today;Mar2011, Vol. 3 Issue 3, p22 

    SEC23A Gene encodes a protein found in the ribosomal-free transitional face of the endoplasmic reticulum (ER) and associated vesicles. This protein plays crucial role in the ER-Golgi protein trafficking. Mutation in the gene results in Cranio-Lenticular-Sutural Dysplasia (CLSD), a novel...

  • Cloning and expression of Trypanosoma congolense major surface protease B2. Honsho, Masaki // Japanese Journal of Veterinary Research;Aug2011, Vol. 59 Issue 2/3, p132 

    The article offers information on a scientific research study on protozoan parasites Trypanosoma congolense major surface protease (TcoMSP- B2). It informs that amino acid sequence of TcoMSP-B2 had higher identity than Trypanosoma brucci MSP-B (ThMSP-B).The study concludes that TcoMSP- B2 is a...

  • Chaperone Requirements for Biosynthesis of the Trypanosome Variant Surface Glycoprotein. Field, Mark C.; Sergeenko, Tatiana; Ya-Nan Wang; Böhm, Susanne; Carrington, Mark // PLoS ONE;2010, Vol. 5 Issue 1, p1 

    Background: Trypanosoma brucei does not respond transcriptionally to several endoplasmic reticulum (ER) stress conditions, including tunicamycin or dithiothreitol, indicating the absence of a conventional unfolded protein response. This suggests divergent mechanisms for quality control (QC) of...

  • The Glycosylphosphatidylinositol-PLC in Trypanosoma brucei Forms a Linear Array on the Exterior of the Flagellar Membrane Before and After Activation. Hanrahan, Orla; Webb, Helena; O'Byrne, Robert; Brabazon, Elaine; Treumann, Achim; Sunter, Jack D.; Carrington, Mark; Voorheis, H. Paul // PLoS Pathogens;Jun2009, Vol. 5 Issue 6, p1 

    Bloodstream forms of Trypanosoma brucei contain a glycosylphosphatidylinositol-specific phospholipase C (GPI-PLC) that cleaves the GPI-anchor of the variable surface glycoprotein (VSG). Its location in trypanosomes has been controversial. Here, using confocal microscopy and surface labelling...

  • Identification of Mimotopes with Diagnostic Potential for Trypanosoma brucei gambiense Variant Surface Glycoproteins Using Human Antibody Fractions. Nieuwenhove, Liesbeth Van; Buscher, Philippe; Balharbi, Fatima; Humbert, Michael; Dieltjens, Tessa; Guisez, Yves; Lejon, Veerle // PLoS Neglected Tropical Diseases;Jun2012, Vol. 6 Issue 6, p1 

    Background: At present, screening of the population at risk for gambiense human African trypanosomiasis (HAT) is based on detection of antibodies against native variant surface glycoproteins (VSGs) of Trypanosoma brucei (T.b.) gambiense. Drawbacks of these native VSGs include culture of...

  • Using the concept of Chou’s pseudo amino acid composition to predict protein subcellular localization: an approach by incorporating evolutionary information and von Neumann entropies. Shao-Wu Zhang; Yun-Long Zhang; Hui-Fang Yang; Chun-Hui Zhao; Quan Pan // Amino Acids;May2008, Vol. 34 Issue 4, p565 

    Abstract  The rapidly increasing number of sequence entering into the genome databank has called for the need for developing automated methods to analyze them. Information on the subcellular localization of new found protein sequences is important for helping to reveal their functions in...

  • A Cell-surface Phylome for African Trypanosomes. Jackson, Andrew P.; Allison, Harriet C.; Barry, J. David; Field, Mark C.; Hertz-Fowler, Christiane; Berriman, Matthew // PLoS Neglected Tropical Diseases;Mar2013, Vol. 7 Issue 3, p1 

    The cell surface of Trypanosoma brucei, like many protistan blood parasites, is crucial for mediating host-parasite interactions and is instrumental to the initiation, maintenance and severity of infection. Previous comparisons with the related trypanosomatid parasites T. cruzi and Leishmania...

  • How Does the VSG Coat of Bloodstream Form African Trypanosomes Interact with External Proteins? Schwede, Angela; Macleod, Olivia J. S.; MacGregor, Paula; Carrington, Mark // PLoS Pathogens;12/31/2015, Vol. 11 Issue 12, p1 

    Abstract: Variations on the statement “the variant surface glycoprotein (VSG) coat that covers the external face of the mammalian bloodstream form of Trypanosoma brucei acts a physical barrier” appear regularly in research articles and reviews. The concept of the impenetrable VSG...

Share

Read the Article

Courtesy of NEW JERSEY STATE LIBRARY

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics