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A new yeast poly(A) polymerase complex involved in RNA quality control

Vanacova, S. and Wolf, J. and Martin, G. and Blank, D. and Dettwiler, S. and Friedlein, A. and Langen, H. and Keith, G. and Keller, W.. (2005) A new yeast poly(A) polymerase complex involved in RNA quality control. PLoS Biology, Vol. 3, H. 6 , e189.

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Official URL: http://edoc.unibas.ch/dok/A5257929

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Abstract

Eukaryotic cells contain several unconventional poly(A) polymerases in addition to the canonical enzymes responsible for the synthesis of poly(A) tails of nuclear messenger RNA precursors. The yeast protein Trf4p has been implicated in a quality control pathway that leads to the polyadenylation and subsequent exosome-mediated degradation of hypomethylated initiator tRNAMet (tRNAiMet). Here we show that Trf4p is the catalytic subunit of a new poly(A) polymerase complex that contains Air1p or Air2p as potential RNA-binding subunits, as well as the putative RNA helicase Mtr4p. Comparison of native tRNAiMet with its in vitro transcribed unmodified counterpart revealed that the unmodified RNA was preferentially polyadenylated by affinity-purified Trf4 complex from yeast, as well as by complexes reconstituted from recombinant components. These results and additional experiments with other tRNA substrates suggested that the Trf4 complex can discriminate between native tRNAs and molecules that are incorrectly folded. Moreover, the polyadenylation activity of the Trf4 complex stimulated the degradation of unmodified tRNAiMet by nuclear exosome fractions in vitro. Degradation was most efficient when coupled to the polyadenylation activity of the Trf4 complex, indicating that the poly(A) tails serve as signals for the recruitment of the exosome. This polyadenylation-mediated RNA surveillance resembles the role of polyadenylation in bacterial RNA turnover.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Growth & Development
05 Faculty of Science > Departement Biozentrum > Former Organization Units Biozentrum > Cell Biology (Keller)
UniBasel Contributors:Keller, Walter
Item Type:Article, refereed
Article Subtype:Research Article
Bibsysno:Link to catalogue
Publisher:Public Library of Science
ISSN:1545-7885
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Last Modified:31 Dec 2015 10:43
Deposited On:22 Mar 2012 13:32

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