TITLE

Codon usage suggests that translational selection has a major impact on protein expression in trypanosomatids

AUTHOR(S)
Horn, David
PUB. DATE
January 2008
SOURCE
BMC Genomics;2008, Vol. 9, Special section p1
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Background: Different proteins are required in widely different quantities to build a living cell. In most organisms, transcription control makes a major contribution to differential expression. This is not the case in trypanosomatids where most genes are transcribed at an equivalent rate within large polycistronic clusters. Thus, trypanosomatids must use post-transcriptional control mechanisms to balance gene expression requirements. Results: Here, the evidence for translational selection, the enrichment of 'favoured' codons in more highly expressed genes, is explored. A set of highly expressed, tandem-repeated genes display codon bias in Trypanosoma cruzi, Trypanosoma brucei and Leishmania major. The tRNA complement reveals forty-five of the sixty-one possible anticodons indicating widespread use of 'wobble' tRNAs. Consistent with translational selection, cognate tRNA genes for favoured codons are over-represented. Importantly, codon usage (Codon Adaptation Index) correlates with predicted and observed expression level. In addition, relative codon bias is broadly conserved among syntenic genes from different trypanosomatids. Conclusion: Synonymous codon bias is correlated with tRNA gene copy number and with protein expression level in trypanosomatids. Taken together, the results suggest that translational selection is the dominant mechanism underlying the control of differential protein expression in these organisms. The findings reveal how trypanosomatids may compensate for a paucity of canonical Pol II promoters and subsequent widespread constitutive RNA polymerase II transcription.
ACCESSION #
38122776

 

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

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

Try another library?
Sign out of this library

Other Topics