Showing papers by "Leonard Guarente published in 1985"
TL;DR: Analysis of 18 yeast RNA polymerase II promoters suggests that two classes of DNA sequences serve as preferred sites for transcription initiation, and replaced some of the normal CYC-1 start sites with one of these sequences, TCGA, and found that transcription initiates at this newly introduced sequence.
Abstract: Transcription initiation of the yeast iso-1-cytochrome c gene (CYC-1) occurs in six major clusters at positions +1, +10, +16, +25, +34, and +43. Potential "TATA elements" lie upstream at positions -154, -106, -52, and -22. Analysis of the TATA region suggests that three of these TATA sequences are functional and contribute to initiation at CYC-1, with the -106 TATA promoting initiation at +1, +10, and +16; the -52 TATA, at +16, +25, +34, and +43; and the -22 TATA, at +34 and +43. Deletions changing the spacing between the TATA sequences and the region of transcription initiation do not change the location of the CYC-1 transcription start points. This finding suggests that at least part of the information determining mRNA initiation sites is encoded within the DNA sequence at the site of transcription initiation. Analysis of 18 yeast RNA polymerase II promoters suggests that two classes of DNA sequences serve as preferred sites for transcription initiation. To test this possibility, we replaced some of the normal CYC-1 start sites with one of these sequences, TCGA, and found that transcription initiates at this newly introduced sequence. These results are in contrast to those from higher eukaryotes, where RNA polymerase II typically initiates transcription a fixed distance downstream from the TATA element. The presence of multiple, functional TATA sequences at CYC-1 is inconsistent with the idea that RNA polymerase or another transcription factor attaches to the template at an upstream activation site and scans for the nearest TATA element.
284 citations
TL;DR: The HAP2 gene is cloned, a locus required for the expression of many cytochromes and respiratory functions in Saccharomyces cerevisiae, and derivatives of these sequences were shown to yield chromosomal disruptions with a Hap2- phenotype.
Abstract: We report here the cloning of the HAP2 gene, a locus required for the expression of many cytochromes and respiratory functions in Saccharomyces cerevisiae. The cloned sequences were found to direct integration of a marked vector to the chromosomal HAP2 locus, and derivatives of these sequences were shown to yield chromosomal disruptions with a Hap2- phenotype. The gene maps 18 centimorgans centromere proximal to ade5 on the left arm of chromosome VII, distinguishing it from any other previously characterized nuclear petite locus. The HAP2 locus encodes a 1.3-kilobase transcript which is present at extremely low levels and which is derepressed in cells grown in media containing nonfermentable carbon sources. Levels of HAP2 mRNA are not reduced in strains bearing a mutation at the HAP3 locus, which is also required for expression of respiratory functions. Models outlining possible interactions of the products of the HAP2 and HAP3 genes are presented.
141 citations