Sucrose control of translation mediated by an upstream open reading frame-encoded peptide.
Regulation of gene expression through translational control is common in many organisms. The Arabidopsis (Arabidopsis thaliana) transcription factor bZIP11 is translational repressed in response to sucrose (Suc), resulting in Suc-regulated changes in amino acid metabolism. The 5' leader of the bZIP11 mRNA harbors several upstream open reading frames (uORFs), of which the second uORF is well conserved among bZIP11 homologous genes. The uORF2 element encodes a Suc control peptide (SC-peptide) of 28 residues that is sufficient for imposing Suc-induced repression of translation (SIRT) on a heterologous mRNA. Detailed analysis of the SC-peptide suggests that it functions as an attenuator peptide. Results suggest that the SC-peptide inhibits bZIP11 translation in response to high Suc levels by stalling the ribosome on the mRNA. The conserved noncanonical AUG contexts of bZIP11 uORFs allow inefficient translational initiation of the uORF, resulting in translation initiation of the scanning ribosome at the AUG codon of the bZIP11 main ORF. The results presented show that Suc-dependent signaling mediates differential translation of mRNAs containing SC-peptides encoding uORFs.
Rahmani
Fatemeh
F
Molecular Plant Physiology, Utrecht University, 3584 CH Utrecht, The Netherlands.
Hummel
Maureen
M
Schuurmans
Jolanda
J
Wiese-Klinkenberg
Anika
A
Smeekens
Sjef
S
Hanson
Johannes
J
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D014176:Protein Biosynthesis / Q000187:drug effects*; D012333:RNA, Messenger / Q000737:chemistry; D017423:Sequence Analysis, RNA; D013395:Sucrose / Q000494:pharmacology*
C112599:ATB2 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D012333:RNA, Messenger; D013395:Sucrose