MICROBIOLOGY AND MOLECULAR BIOLOGY REVIEWS,1092-2172/98/$04.0010June 1998, p. 334–361 Vol. 62, No. 2Copyright © 1998, American Society for MicrobiologyYeast Carbon Catabolite Repression†JUANA M. GANCEDO*Instituto de Investigaciones Biome´dicas, Unidad de Bioquı´mica yGene´tica de Levaduras, CSIC, 28029 Madrid, SpainINTRODUCTION.......................................................................................................................................................334LEVELS OF CONTROL............................................................................................................................................334ELEMENTS OF THE SYSTEM...............................................................................................................................336Activators .................................................................................................................................................................336The Hap2/3/4/5 complex.....................................................................................................................................336Gal4.......................................................................................................................................................................337Mal63....................................................................................................................................................................337Adr1 ......................................................................................................................................................................338Other activators ..................................................................................................................................................338Repressors................................................................................................................................................................339The Mig1 complex...............................................................................................................................................339Other repressors .................................................................................................................................................340Intermediary Elements...........................................................................................................................................341The Snf1 complex................................................................................................................................................341The Glc7 complex ...............................................................................................................................................342Elements Involved in Glucose Signaling .............................................................................................................343Elements Which Play an Indirect Role................................................................................................................345The Snf/Swi complex and the Spt proteins.....................................................................................................345The mediator .......................................................................................................................................................346The Ada/Gcn5 complex ......................................................................................................................................347Other elements....................................................................................................................................................347REGULATION OF SPECIFIC GENES...................................................................................................................347The GAL Genes.......................................................................................................................................................347SUC2 .........................................................................................................................................................................348FBP1 .........................................................................................................................................................................349ADH2 ........................................................................................................................................................................350CYC1..........................................................................................................................................................................350Other Genes.............................................................................................................................................................350CONCLUSIONS AND PERSPECTIVES.................................................................................................................352ACKNOWLEDGMENTS ...........................................................................................................................................353REFERENCES ............................................................................................................................................................353INTRODUCTIONSaccharomyces cerevisiae and many other yeasts may thriveon a variety of carbon sources, but glucose and fructose are thepreferred ones. When one of these sugars is present, the en-zymes required for the utilization of alternative carbon sourcesare synthesized at low rates or not at all. This phenomenon isknown as carbon catabolite repression, or simply cataboliterepression, and since no “catabolite” derived from glucose andinvolved in the repression has been yet identified, the term“glucose repression” has also been proposed. In this review, Istill use the term “catabolite repression” as well as glucoserepression, to stress that other sugars, such as galactose ormaltose, are able to affect the synthesis of enzymes repressedby glucose (Table 1).A comprehensive picture of the mechanism(s) of cataboliterepression is not yet available, in spite of the accumulation ofinformation on the subject (for earlier reviews, see references95, 96a, 96b, 124, 163, 289, and 346). Although the solution ofthe puzzle has progressed, important pieces are still
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