The aim of this work was to establish the relative contribution of genetic regulation of the <I>PYK1</I>, <I>PFK1</I> and <I>PFK2</I> genes to the control of glycolysis. A series of isogenic mutant strains were constructed where the promoters and 5' untranslated sequences of the <I>PYK1, PFK1</I> and <I>PFK2</I> genes were replaced with those from <I>PGK1</I>. In addition , a second series of mutant strains were constructed where synthesis of Pyk1p and Pflkp was driven by the <I>PGK1<sub>Δuas</sub></I> promoter. These latter series of mutants were designed to contain weak expression of Pyklp and Pflkp. Analysis of UKC1 (<I>PGK::PYK1)</I> in shake flask cultures revealed similar growth rates on glucose and on lactate and similar rates of ethanol production and glucose consumption to those of the wild-type strain. This suggested that the native genetic regulation did not appear to play a significant role in the control of glycolysis. Nonetheless, analysis of this strain in the fermentor revealed that genetic regulation of <I>PYK1</I> may be important in co-ordinating Pyk1p synthesis, under the conditions studied. Analysis of YKC11 (<I>PGK<sub>Δuas</sub>::PYK1)</I> in both shake flask and fermentor experiments showed that genetic control was important in maintaining Pyk1p levels in order to sustain glycolytic flux. Shake flask analysis of the single and double <I>PFK</I> mutants under the control of the <I>PGK1</I> promoter revealed that the genetic regulation of the <I>PFK1</I> and <I>PFK2</I> genes did not appear to be important in the control of glycolysis. Weak expression of the <I>PFK1</I> and <I>PFK2</I> genes, under the control of the <I>PGK<sub>Δuas</sub></I> promoter showed the importance of genetic regulation in maintaining Pflkp levels to support glycolytic flux, under the conditions studied.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:320258 |
| Date | January 1995 |
| Creators | Crimmins, Kay |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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