Epigenetics of the yeast galactose genetic switch.
The transcriptional activation of enzymes involved in galactose utilization (GAL genes) in Saccharomyces cerevisiae is regulated by a complex interplay between three regulatory proteins encoded by GAL4 (transcriptional activator), GAL3 (signal transducer) and GAL80 (repressor). The relative concentrations of the signal transducer and the repressor are maintained by autoregulation. Cells disabled for autoregulation exhibit phenotypes distinctly different from that of the wild type cells, enabling us to explore the biological significance of autoregulation. The redundancy in signal transduction due to the presence of GAL1 (alternate signal transducer) also makes it a suitable model to understand the phenomenon of epigenetics. In this article we review some of the recent attempts made to understand the importance of epigenetics in the establishment of cellular and transcriptional memory.
Bhat
Paike Jayadeva
PJ
Laboratory of Molecular Genetics, School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400 076, India. jayadeva@iitb.ac.in
Iyer
Revathi S
RS
D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D044127:Epigenesis, Genetic; D019143:Evolution, Molecular; D025461:Feedback, Physiological; D005686:Galactokinase / Q000378:metabolism / Q000502:physiology; D005690:Galactose / Q000378:metabolism*; D016681:Genome, Fungal; D005838:Genotype; D008957:Models, Genetic; D010641:Phenotype; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; C052130:GAL4 protein, S cerevisiae; C055002:GAL80 protein, S cerevisiae; C099289:Gal3 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C524219:GAL1 protein, S cerevisiae; D005686:Galactokinase; D005690:Galactose