Genetic and molecular analysis of the CDC68 gene of Saccharomyces cerevisiae.
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Date
1991
Authors
Rowley, Adele.
Journal Title
Journal ISSN
Volume Title
Publisher
Dalhousie University
Abstract
Description
The cell cycle of the budding yeast Saccharomyces cerevisiae has been investigated through the study of conditional cdc mutations that specifically affect cell-cycle performance. Cells bearing the cdc68-1 mutation are temperature-sensitive for the performance of the G1 regulatory event, Start. This study describes both genetic and molecular evidence that suggests that the CDC68 gene plays a role in transcription. The abundance of transcripts from several unrelated genes has been found to decrease in cdc68-1 mutant cells after transfer to the restrictive temperature while at least one transcript, from the HSP82 gene, persists in an unusual fashion. Thus the cdc68-1 mutation has both positive and negative effects on gene expression. Among transcripts that rapidly become depleted in cdc68-1 mutant cells are those of the G1-cyclin genes CLN1, CLN2 and CLN3/WHI1/DAF1, whose activity has been previously shown to be required for the performance of Start. The decreased abundance of cyclin transcripts in cdc68-1 mutant cells, coupled with suppression of cdc68-1-mediated Start arrest by a hyperactive cyclin mutation, demonstrates that the CDC68 gene affects Start through effects on cyclin gene expression.
The CDC68 gene encodes a 1035 amino acid protein with a highly acidic and serine-rich carboxyl-terminus. Two temperature-sensitive mutations have been localized to the N-terminal third of the predicted Cdc68 protein. Surpisingly, however, this region of the CDC68 open reading frame can be deleted with little effect on cell proliferation. Thus, removal of this region appears less deleterious than the presence of particular point mutations.
The pleiotropic effects of cdc68 mutations, gene dosage effects, as well as structural and phenotypic similarities to other genes, suggest that the function of the Cdc68 protein may involve interaction with chromatin to influence transcription from a large number of promoters.
Thesis (Ph.D.)--Dalhousie University (Canada), 1991.
The CDC68 gene encodes a 1035 amino acid protein with a highly acidic and serine-rich carboxyl-terminus. Two temperature-sensitive mutations have been localized to the N-terminal third of the predicted Cdc68 protein. Surpisingly, however, this region of the CDC68 open reading frame can be deleted with little effect on cell proliferation. Thus, removal of this region appears less deleterious than the presence of particular point mutations.
The pleiotropic effects of cdc68 mutations, gene dosage effects, as well as structural and phenotypic similarities to other genes, suggest that the function of the Cdc68 protein may involve interaction with chromatin to influence transcription from a large number of promoters.
Thesis (Ph.D.)--Dalhousie University (Canada), 1991.
Keywords
Biology, Molecular., Biology, Genetics.