Abstract
The yeast regulatory gene CAT3 has an essential function for the derepression of several glucose-repressible enzymes. Therefore, cat3 mutants are unable to grow on maltose or on non-fermentable carbon sources. Unlike the point mutants isolated previously, cat3 null allele strains also failed to utilize raffinose or galactose as sole carbon sources. Sequencing of an 1.6-kb HindIII- BglII fragment complementing cat3 mutations revealed an open reading frame of 322 codons, size of which is in good agreement with the 1.3-kb size of mRNA. No significant similarities with previously sequenced genes could be detected. CAT3- lacZ fusions confirmed the proposed reading frame. A CAT3- lacZ fusion encoding 307 amino acids of CAT3 was able to complement the growth defects of cat3 point mutants and null allele strains. Assay of β-galactosidase activity under different growth conditions indicated a constitutive expression of the CAT3 gene product. Cellular fractionation studies showed the nuclear localization of the CAT3 protein.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
