title: The arginine attenuator peptide interferes with the ribosome peptidyl transferase center.
abstract: The fungal arginine attenuator peptide (AAP) is encoded by a regulatory upstream open reading frame (uORF). The AAP acts as a nascent peptide within the ribosome tunnel to stall translation in response to arginine (Arg). The effect of AAP and Arg on ribosome peptidyl transferase center (PTC) function was analyzed in Neurospora crassa and wheat germ translation extracts using the transfer of nascent AAP to puromycin as an assay. In the presence of a high concentration of Arg, the wild-type AAP inhibited PTC function, but a mutated AAP that lacked stalling activity did not. While AAP of wild-type length was most efficient at stalling ribosomes, based on primer extension inhibition (toeprint) assays and reporter synthesis assays, a window of inhibitory function spanning four residues was observed at the AAP's C terminus. The data indicate that inhibition of PTC function by the AAP in response to Arg is the basis for the AAP's function of stalling ribosomes at the uORF termination codon. Arg could interfere with PTC function by inhibiting peptidyltransferase activity and/or by restricting PTC A-site accessibility. The mode of PTC inhibition appears unusual because neither specific amino acids nor a specific nascent peptide chain length was required for AAP to inhibit PTC function.
authors.affiliation: Department of Biology, Texas A&M University, College Station, Texas, USA.
authors.forename: Jiajie
authors.initials: J
authors.lastname: Wei
authors.forename: Cheng
authors.initials: C
authors.lastname: Wu
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Sachs
mesh_terms: D000595:Amino Acid Sequence; D001120:Arginine / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D019733:Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002474:Cell-Free System; D018388:Codon, Terminator; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009492:Neurospora crassa / Q000235:genetics / Q000378:metabolism; D016366:Open Reading Frames; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010458:Peptidyl Transferases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
chemical_list: D018388:Codon, Terminator; D005656:Fungal Proteins; D010446:Peptide Fragments; D012331:RNA, Fungal; D012333:RNA, Messenger; C116079:arginine attenuator peptide; D001120:Arginine; D010458:Peptidyl Transferases; D019733:Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor