The cis-acting gibberellin response complex in high pI alpha-amylase gene promoters. Requirement of a coupling element for high-level transcription.
In cereal alpha-amylase gene promoters the cis-acting gibberellin response element (GARE) is required for increased transcription in the presence of gibberellin. In low-isoelectric point (pI) alpha-amylase gene promoters a second type of cis element, termed a coupling element, must also be present in a specific position near the GARE; otherwise, the level of transcription in the presence of gibberellin is only a few percent of maximum. The coupling element may help determine where and when in development high-level, hormonally regulated transcription will occur. Such coupling elements have not yet been shown to be necessary for high-level transcription from high-pI alpha-amylase gene promoters. Here we use quantitative transient expression assays to show that a high-pI promoter truncated to -300 is a weak promoter due to the absence of a functional coupling element in the vicinity of the GARE. Gibberellin-induced transcription increases substantially when coupling element function is provided, either by appending upstream regions normally attached to the promoter or by inserting a defined coupling element from a low-pI promoter. Thus, in a second type of gibberellin-regulated promoter coupling element function was found to be crucial for hormone regulation to result in high-level transcription.
Division of Hematology-Oncology, Washington University School of Medicine, St. Louis, Missouri 63110.
J C
JC
Rogers
M B
MB
Lanahan
S W
SW
Rogers
D000595:Amino Acid Sequence; D001483:Base Sequence; D002523:Edible Grain / Q000201:enzymology* / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects*; D015971:Gene Expression Regulation, Enzymologic; D017343:Genes, Plant; D005875:Gibberellins / Q000494:pharmacology*; D005966:Glucuronidase / Q000096:biosynthesis / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D000516:alpha-Amylases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism
D005875:Gibberellins; D007527:Isoenzymes; D000516:alpha-Amylases; D005966:Glucuronidase