Publication Date:
1990-04-27
Description:
Light-dependent expression of rbcS, the gene encoding the small subunit of ribulose-1,5-bisphosphate carboxylase, which is the key enzyme involved in carbon fixation in higher plants, is regulated at the transcriptional level. Sequence analysis of the gene has uncovered a conserved GT motif in the -150 to -100 region of many rbcS promoters. This motif serves as the binding site of a nuclear factor, designated GT-1. Analysis of site-specific mutants of pea rbcS-3A promoter demonstrated that GT-1 binding in vitro is correlated with light-responsive expression of the rbcS promoter in transgenic plants. However, it is not known whether factors other than GT-1 might also be required for activation of transcription by light. A synthetic tetramer of box II (TGTGTGGTTAATATG), the GT-1 binding site located between -152 to -138 of the rbcS-3A promoter, inserted upstream of a truncated cauliflower mosaic virus 35S promoter is sufficient to confer expression in leaves of transgenic tobacco. This expression occurs principally in chloroplast-containing cells, is induced by light, and is correlated with the ability of box II to bind GT-1 in vitro. The data show that the binding site for GT-1 is likely to be a part of the molecular light switch for rbcS activation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lam, E -- Chua, N H -- New York, N.Y. -- Science. 1990 Apr 27;248(4954):471-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Plant Molecular Biology, Rockefeller University, New York, NY 10021.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2330508" target="_blank"〉PubMed〈/a〉
Keywords:
Base Sequence
;
Binding Sites
;
Chloramphenicol O-Acetyltransferase/genetics
;
Cloning, Molecular
;
DNA-Binding Proteins/*metabolism
;
Gene Expression Regulation/*physiology
;
Genetic Vectors
;
*Light
;
Molecular Sequence Data
;
Mutation
;
Nuclear Proteins/*metabolism
;
Plant Proteins/*metabolism
;
*Plants, Toxic
;
Promoter Regions, Genetic/genetics
;
Ribulose-Bisphosphate Carboxylase/*genetics
;
Tobacco/enzymology/*genetics
;
Transcription, Genetic/radiation effects
;
Transformation, Genetic
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
