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Amino termini of many yeast proteins map to downstream start codons.

ABSTRACT: Comprehensive knowledge of proteome complexity is crucial to understanding cell function. Amino termini of yeast proteins were identified through peptide mass spectrometry on glutaraldehyde-treated cell lysates as well as a parallel assessment of publicly deposited spectra. An unexpectedly large fraction of detected amino-terminal peptides (35%) mapped to translation initiation at AUG codons downstream of the annotated start codon. Many of the implicated genes have suboptimal sequence contexts for translation initiation near their annotated AUG, and their ribosome profiles show elevated tag densities consistent with translation initiation at downstream AUGs as well as their annotated AUGs. These data suggest that a significant fraction of the yeast proteome derives from initiation at downstream AUGs, increasing significantly the repertoire of encoded proteins and their potential functions and cellular localizations.

SUBMITTER: Fournier CT

PROVIDER: S-EPMC3519384 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature

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Amino termini of many yeast proteins map to downstream start codons.

Fournier Claire T CT Cherny Justin J JJ Truncali Kris K Robbins-Pianka Adam A Lin Miin S MS Krizanc Danny D Weir Michael P MP

Journal of proteome research 20121121 12

Comprehensive knowledge of proteome complexity is crucial to understanding cell function. Amino termini of yeast proteins were identified through peptide mass spectrometry on glutaraldehyde-treated cell lysates as well as a parallel assessment of publicly deposited spectra. An unexpectedly large fraction of detected amino-terminal peptides (35%) mapped to translation initiation at AUG codons downstream of the annotated start codon. Many of the implicated genes have suboptimal sequence contexts f ...[more]

PMID: 23140384

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