title: A nascent polypeptide domain that can regulate translation elongation.
abstract: The evolutionarily conserved fungal arginine attenuator peptide (AAP), as a nascent peptide, stalls the translating ribosome in response to the presence of a high concentration of the amino acid arginine. Here we examine whether the AAP maintains regulatory function in fungal, plant, and animal cell-free translation systems when placed as a domain near the N terminus or internally within a large polypeptide. Pulse-chase analyses of the radiolabeled polypeptides synthesized in these systems indicated that wild-type AAP functions at either position to stall polypeptide synthesis in response to arginine. Toeprint analyses performed to map the positions of stalled ribosomes on transcripts introduced into the fungal system revealed that ribosome stalling required translation of the AAP coding sequence. The positions of the stalled ribosomes were consistent with the sizes of the radiolabeled polypeptide intermediates. These findings demonstrate that an internal polypeptide domain in a nascent chain can regulate eukaryotic translational elongation in response to a small molecule. Apparently the peptide-sensing features are conserved in fungal, plant, and animal ribosomes. These data provide precedents for translational strategies that would allow domains within nascent polypeptide chains to modulate gene expression.
authors.affiliation: Department of Environmental and Biomolecular Systems, OGI School of Science & Engineering, Oregon Health & Science University, Beaverton, OR 97006-8921, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Fang
authors.forename: Christina C
authors.initials: CC
authors.lastname: Spevak
authors.forename: Cheng
authors.initials: C
authors.lastname: Wu
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Sachs
mesh_terms: D019733:Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor / Q000235:genetics / Q000378:metabolism*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D013997:Time Factors
chemical_list: D002593:Cetrimonium Compounds; D005656:Fungal Proteins; D010446:Peptide Fragments; C116079:arginine attenuator peptide; D019733:Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor; D000077286:Cetrimonium