Eukaryotic peptide chain release factor 1 participates in translation termination of specific cysteine-poor prolamines in rice endosperm. (April 2019)

• Record Type: Journal Article
• Authors: Elakhdar, Ammar; Ushijima, Tomokazu; Fukuda, Masako; Yamashiro, Noriko; Kawagoe, Yasushi; Kumamaru, Toshihiro
• Is Part Of: Plant science. Volume 281(2019)
• Page Start: 223
• Page End: 231
• Publication Date: 2019-04
• Subjects: Prolamine -- eRF1 -- Storage protein -- Rice -- Termination codon -- Genetic linkage map; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2018.12.006
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: ESP1 -encoded eRF1 releases nascent polypeptides during translation termination. Expression of ESP1/eRF1 only occurs during early seed development. ESP1/eRF1 selectively recognizes the UAA or UAG termination codon. ESP1/eRF1 is a key factor in the prolamine accumulation pathway of rice endosperm. Abstract: Prolamines are alcohol-soluble proteins classified as either cysteine-poor (CysP) or cysteine-rich (CysR) based on whether they can be alcohol-extracted without or with reducing agents, respectively. In rice esp1 mutants, various CysP prolamines exhibit both reduced and normal amounts of isoelectric focusing bands, indicating that the mutation affects only certain prolamine classes. To examine the genetic regulation of CysP prolamine synthesis and accumulation, we constructed a high-resolution genetic linkage map of ESP1 . The ESP1 gene was mapped to within a 20 kb region on rice chromosome 7. Sequencing analysis of annotated genes in this region revealed a single-nucleotide polymorphism within eukaryotic peptide chain release factor ( eRF1 ), which participates in stop-codon recognition and nascent-polypeptide release from ribosomes during translation. A subsequent complementation test revealed that ESP1 encodes eRF1. We also identified UAA as the stop codon of CysP prolamines with reduced concentration in esp1 mutants. Recognition assays and microarray analysis confirmed that ESP1/eRF1 recognizes UAA/UAG, but not UGA. Our results provide convincing evidence that ESP1/eRF1 participates in the translation termination of CysP prolamines during seed development.