Login | Register

Regulation of the GCV3 gene in Saccharomyces cerevisiae


Regulation of the GCV3 gene in Saccharomyces cerevisiae

Zheng, Yun (2000) Regulation of the GCV3 gene in Saccharomyces cerevisiae. Masters thesis, Concordia University.

[thumbnail of MQ47798.pdf]
Text (application/pdf)


The glycine cleavage system (GCS) is a multienzyme complex containing four proteins. The GCS, which is important for the growth and viability of organisms ranging from bacteria to humans, catalyses the oxidative cleavage of glycine into CO 2 and NH 3 . Concomitantly it generates the C1-donor 5,10-methylenetetrahydrofolate and the electron donor NADH. NH 3 is an important precursor for cellular nitrogen metabolism. The C1-donor 5,10-methylenetetrahydrofolate is a precursor for the biosynthesis of C1-end products such as adenine, thymidylate, serine and methionine. The goal of my research was to study the regulatory mechanisms controlling GCS activity. The expression of GCV3 , a yeast gene that codes for one of the four GCS subunits, was analyzed in detail. This revealed that GCV3 expression is regulated by the availability of glycine, and cellular demand for the metabolic products of glycine cleavage. 10 mM glycine in minimal medium (SD) induced GCV3 expression about 4-fold. Supplementing with the C1-metabolic end products repressed GCV3 expression about 3-fold. Both glycine induction and repression by the C1-end products were found to be Bas1p-dependent. The upstream promoter elements required for regulation by Bas1p were localized. Expression of GCV3 is also subject to the general control system in a Gcn4p-dependent fashion. The elements utilized by Gcn4p have been characterized. A GATAA sequence located at -167bp upstream of the start codon is used by the nitrogen regulation system. Gcr1p, a transcription activator for glycolytic genes, is involved in regulating GCV3 in the presence of glucose. Evidences are also presented for an as yet unidentified regulator that represses expression in SD. Additional results presented in this thesis suggest that Rap1p, Nil1p, Ure2p and Deb1p also regulate GCV3

Divisions:Concordia University > Faculty of Arts and Science > Chemistry and Biochemistry
Item Type:Thesis (Masters)
Authors:Zheng, Yun
Pagination:xii, 109 leaves ; 29 cm.
Institution:Concordia University
Degree Name:M.Sc.
Thesis Supervisor(s):Storms, Reginald
Identification Number:QH 470 S23Z44 2000
ID Code:1033
Deposited By: Concordia University Library
Deposited On:27 Aug 2009 17:16
Last Modified:13 Jul 2020 19:48
Related URLs:
All items in Spectrum are protected by copyright, with all rights reserved. The use of items is governed by Spectrum's terms of access.

Repository Staff Only: item control page

Downloads per month over past year

Research related to the current document (at the CORE website)
- Research related to the current document (at the CORE website)
Back to top Back to top