The 3'-untranslated region of a rice alpha-amylase gene functions as a sugar-dependent mRNA stability determinant

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 95; no. 11; pp. 6543 - 6547
• Main Authors: Chan, M.T. (Academia Sinica, Taiwan, Republic of China.), Yu, S.M
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 26.05.1998; National Acad Sciences; National Academy of Sciences; The National Academy of Sciences
• Subjects: ALFA AMILASA; ALPHA AMYLASE; alpha-Amylases - genetics; ALPHAAMY3 GENE; ARN MENSAJERO; ARN MESSAGER; Base Sequence; Biological Sciences; Botany; CELL CULTURE; Cell growth; Cell lines; CELL SUSPENSIONS; CULTIVO DE CELULAS; CULTURE DE CELLULE; DEGRADACION; DEGRADATION; DISPONIBILIDAD DE NUTRIENTES; DISPONIBILITE D'ELEMENT NUTRITIF; ESTABILIDAD; GENE; GENES; Genes, Plant; GENETIC TRANSFORMATION; Half lives; LUCIFERASE; MESSENGER RNA; Molecular Sequence Data; NUTRIENT AVAILABILITY; Oryza - genetics; ORYZA SATIVA; OXIDOREDUCTASES; OXIDORREDUCTASAS; OXYDOREDUCTASE; Plant Proteins - genetics; PROMOTERS; REPORTER GENES; Repression; Ribonucleic acid; Rice; RNA; RNA stability; RNA, Messenger - genetics; RNA, Messenger - metabolism; SACCHAROSE; STABILITE; STABILITY; STRUCTURAL GENES; SUCROSA; SUCROSE; Sugar; TRANSCRIPCION; TRANSCRIPTION; TRANSFORMACION GENETICA; TRANSFORMATION GENETIQUE; Transformed cell line; Untranslated regions
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.95.11.6543

In plants, sugar feedback regulation provides a mechanism for control of carbohydrate allocation and utilization among tissues and organs. The sugar repression of alpha-amylase gene expression in rice provides an ideal model for studying the mechanism of sugar feedback regulation. We have shown previously that sugar repression of alpha-amylase gene expression in rice suspension cells involves control of both transcription rate and mRNA stability. The alpha-amylase mRNA is significantly more stable in sucrose-starved cells than in sucrose-provided cells. To elucidate the mechanism of sugar-dependent mRNA turnover, we have examined the effect of alpha Amy3 3' untranslated region (UTR) on mRNA stability by functional analyses in transformed rice suspension cells. We found that the entire alpha Amy3 3' UTR and two of its subdomains can independently mediate sugar-dependent repression of reporter mRNA accumulation. Analysis of reporter mRNA half-lives demonstrated that the entire alpha Amy3 3' UTR and the two subdomains each functioned as a sugar-dependent destabilizing determinant in the turnover of mRNA. Nuclear run-on transcription analysis further confirmed that the alpha Amy3 3' UTR and the two subdomains did not affect the transcription rate of promoter. The identification of sequence elements in the alpha-amylase mRNA that dictate the differential stability has very important implications for the study of sugar-dependent mRNA decay mechanisms