Expression of the gene encoding subunit II of yeast QH2: Cytochromecoxidoreductase is regulated by multiple factors

✍ Scribed by J. C. Dorsman; L. A. Grivell

• Book ID: 104717553
• Publisher: Springer-Verlag
• Year: 1990
• Tongue: English
• Weight: 764 KB
• Volume: 17
• Category: Article
• ISSN: 0172-8083
• DOI: 10.1007/bf00313072

✦ Synopsis

In Saccharomyces cerevisiae, the COR2 gene codes for the 40 kDa subunit II of the QH2: cytochrome c oxidoreductase, an enzyme of the mitochondrial respiratory chain. Regions in the 5' flank of this gene important for regulated expression were identified by assaying beta-galactosidase activities in cells carrying different COR2-lacZ fusion genes. Sequences downstream of position -201 relative to the translational initiation codon are sufficient to confer regulation by carbon source, whereas sequences downstream of position -153 do not give rise to significant expression. A binding site for the abundant general transcription factor GFI is present in the region between -201 and -153 just upstream from sequences which resemble the consensus DNA recognition sequence of the regulatory protein complex HAP2/HAP3: 5'-TNATTGGT-3'. By quantitating RNA levels and assaying beta-galactosidase activities we show that synthesis of COR2, which is not a hemoprotein, is regulated by HAP1, HAP2/HAP3 and heme.