Characterization of a Novel Class I Transcription Factor A (CITFA) Subunit That Is Indispensable for Transcription by the Multifunctional RNA Polymerase I of Trypanosoma brucei

Handle URI:
http://hdl.handle.net/10754/554100
Title:
Characterization of a Novel Class I Transcription Factor A (CITFA) Subunit That Is Indispensable for Transcription by the Multifunctional RNA Polymerase I of Trypanosoma brucei
Authors:
Nguyen, T. N.; Nguyen, B. N.; Lee, J. H.; Panigrahi, A. K.; Gunzl, A.
Abstract:
Trypanosoma brucei is the only organism known to have evolved a multifunctional RNA polymerase I (pol I) system that is used to express the parasite's ribosomal RNAs, as well as its major cell surface antigens, namely, the variant surface glycoprotein (VSG) and procyclin, which are vital for establishing successful infections in the mammalian host and the tsetse vector, respectively. Thus far, biochemical analyses of the T. brucei RNA pol I transcription machinery have elucidated the subunit structure of the enzyme and identified the class I transcription factor A (CITFA). CITFA binds to RNA pol I promoters, and its CITFA-2 subunit was shown to be absolutely essential for RNA pol I transcription in the parasite. Tandem affinity purification (TAP) of CITFA revealed the subunits CITFA-1 to -6, which are conserved only among kinetoplastid organisms, plus the dynein light chain DYNLL1. Here, by tagging CITFA-6 instead of CITFA-2, a complex was purified that contained all known CITFA subunits, as well as a novel proline-rich protein. Functional studies carried out in vivo and in vitro, as well as a colocalization study, unequivocally demonstrated that this protein is a bona fide CITFA subunit, essential for parasite viability and indispensable for RNA pol I transcription of ribosomal gene units and the active VSG expression site in the mammalian-infective life cycle stage of the parasite. Interestingly, CITFA-7 function appears to be species specific, because expression of an RNA interference (RNAi)-resistant CITFA-7 transgene from Trypanosoma cruzi could not rescue the lethal phenotype of silencing endogenous CITFA-7.
KAUST Department:
Biosciences Core Lab
Citation:
Characterization of a Novel Class I Transcription Factor A (CITFA) Subunit That Is Indispensable for Transcription by the Multifunctional RNA Polymerase I of Trypanosoma brucei 2012, 11 (12):1573 Eukaryotic Cell
Journal:
Eukaryotic Cell
Issue Date:
26-Oct-2012
DOI:
10.1128/EC.00250-12
PubMed ID:
23104567
PubMed Central ID:
PMC3536272
Type:
Article
ISSN:
1535-9778; 1535-9786
Additional Links:
http://ec.asm.org/cgi/doi/10.1128/EC.00250-12
Appears in Collections:
Articles; Biosciences Core Lab; Biosciences Core Lab

Full metadata record

DC FieldValue Language
dc.contributor.authorNguyen, T. N.en
dc.contributor.authorNguyen, B. N.en
dc.contributor.authorLee, J. H.en
dc.contributor.authorPanigrahi, A. K.en
dc.contributor.authorGunzl, A.en
dc.date.accessioned2015-05-18T21:45:55Zen
dc.date.available2015-05-18T21:45:55Zen
dc.date.issued2012-10-26en
dc.identifier.citationCharacterization of a Novel Class I Transcription Factor A (CITFA) Subunit That Is Indispensable for Transcription by the Multifunctional RNA Polymerase I of Trypanosoma brucei 2012, 11 (12):1573 Eukaryotic Cellen
dc.identifier.issn1535-9778en
dc.identifier.issn1535-9786en
dc.identifier.pmid23104567en
dc.identifier.doi10.1128/EC.00250-12en
dc.identifier.urihttp://hdl.handle.net/10754/554100en
dc.description.abstractTrypanosoma brucei is the only organism known to have evolved a multifunctional RNA polymerase I (pol I) system that is used to express the parasite's ribosomal RNAs, as well as its major cell surface antigens, namely, the variant surface glycoprotein (VSG) and procyclin, which are vital for establishing successful infections in the mammalian host and the tsetse vector, respectively. Thus far, biochemical analyses of the T. brucei RNA pol I transcription machinery have elucidated the subunit structure of the enzyme and identified the class I transcription factor A (CITFA). CITFA binds to RNA pol I promoters, and its CITFA-2 subunit was shown to be absolutely essential for RNA pol I transcription in the parasite. Tandem affinity purification (TAP) of CITFA revealed the subunits CITFA-1 to -6, which are conserved only among kinetoplastid organisms, plus the dynein light chain DYNLL1. Here, by tagging CITFA-6 instead of CITFA-2, a complex was purified that contained all known CITFA subunits, as well as a novel proline-rich protein. Functional studies carried out in vivo and in vitro, as well as a colocalization study, unequivocally demonstrated that this protein is a bona fide CITFA subunit, essential for parasite viability and indispensable for RNA pol I transcription of ribosomal gene units and the active VSG expression site in the mammalian-infective life cycle stage of the parasite. Interestingly, CITFA-7 function appears to be species specific, because expression of an RNA interference (RNAi)-resistant CITFA-7 transgene from Trypanosoma cruzi could not rescue the lethal phenotype of silencing endogenous CITFA-7.en
dc.relation.urlhttp://ec.asm.org/cgi/doi/10.1128/EC.00250-12en
dc.rightsArchived with thanks to Eukaryotic Cellen
dc.titleCharacterization of a Novel Class I Transcription Factor A (CITFA) Subunit That Is Indispensable for Transcription by the Multifunctional RNA Polymerase I of Trypanosoma bruceien
dc.typeArticleen
dc.contributor.departmentBiosciences Core Laben
dc.identifier.journalEukaryotic Cellen
dc.identifier.pmcidPMC3536272en
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, Connecticut, USAen
dc.contributor.institutionDepartment of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, Connecticut, USAen
dc.contributor.institutionSeattle Biomedical Research Institute, Seattle, Washington, USAen
dc.contributor.institutionHarvard Medical School, Boston, Massachusetts, USAen
kaust.authorPanigrahi, Aswini Kumaren

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