CCR4 is a glucose-regulated transcription factor whose leucine-rich repeat binds several proteins important for placing CCR4 in its proper promoter context.
The yeast CCR4 protein is required for the expression of a number of genes involved in nonfermentative growth, including glucose-repressible ADH2, and is the only known suppressor of mutations in the SPT6 and SPT10 genes, two genes which are believed to be involved in chromatin maintenance. We show here that although CCR4 did not bind DNA under the conditions tested, it was able to activate transcription when fused to a heterologous DNA-binding domain. The transcriptional activation ability of CCR4, in contrast to that of many other activators, was glucose regulated. Two activation domains one of which was glucose responsive and encompassed a glutamine-proline-rich region similar to that found in other eukaryotic transcriptional factors were identified. The two transactivation regions, when separated from the leucine-rich repeat and the C terminus of CCR4, were unable to complement a defective ccr4 allele, suggesting that the leucine-rich repeat and the C terminus make contacts that link the activation regions to the proper gene context. Native immunoprecipitation of CCR4 revealed that CCR4 was complexed with at least four other proteins. The leucine-rich repeat of CCR4 was both necessary and sufficient for interaction with at least two of these factors. We propose that the leucine-rich repeat links CCR4 through its associated factors to its promoter context at ADH2 and other loci where it is required for proper transcriptional regulation.
Draper
M P
MP
Department of Biochemistry and Molecular Biology, University of New Hampshire, Durham 03824.
Liu
H Y
HY
Nelsbach
A H
AH
Mosley
S P
SP
Denis
C L
CL
D000426:Alcohol Dehydrogenase / Q000096:biosynthesis / Q000235:genetics; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli; D005656:Fungal Proteins / Q000096:biosynthesis / Q000378:metabolism*; D005800:Genes, Fungal; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D012260:Ribonucleases; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases; D013728:Terminator Regions, Genetic; D014157:Transcription Factors / Q000096:biosynthesis / Q000378:metabolism*; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000378:metabolism; D000099160:LexA Repressor Protein
D000426:Alcohol Dehydrogenase; D001426:Bacterial Proteins; D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D012260:Ribonucleases; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases; D014157:Transcription Factors; D001616:beta-Galactosidase; D000099160:LexA Repressor Protein; C078657:CCR4 protein, S cerevisiae