Discovering new functions of GABA-responsive transcription factors in S. cerevisiae

GULIAS JUAN FACUNDO; BERMÚDEZ-MORETTI, MARIANA; MUÑOZ SEBASTIAN ANIBAL; CORREA-GARCÍA, SUSANA RAQUEL; GUILLEN-VALENCIA JENNIFFER

Capital Federal

Jornada; jornadas interdisciplinarias de Química Biológica; 2017

Departamento de Química Biológica de la facultad de Ciencias Exactas y Naturales de la UBA.

Área: Biología Molecular Discovering new functions of GABA-responsive transcription factors in S. cerevisiaeMuñoz SA, Gulías JF, Valencia-Guillén J, Correa-García S and Bermúdez-Moretti M.Departamento de Química Biológica, FCEN, UBA - IQUIBICEN, CONICET. CABA, Argentina munozsebastian@qb.fcen.uba.arLaboratorio 9 - Centro multidisciplinario 1.S.cerevisiae cells can adapt to a great variety of nutrients. To get the major profits of them, not only general transcriptional and translational mechanisms are triggered, but also specialized transcription factors (TFs) are activated generating activation or repression of specific sets of genes. Amino acids can be metabolized and used as nitrogen and carbon sources or as building blocks for protein biosynthesis. When several amino acids are available, yeast cells use them in a well-defined order as a consequence of a coordinated gene regulation. UGA genes encode the enzymes involved GABA utilization and the TFs Uga3 and Dal81 induce these genes in the presence of GABA. While Dal81 is a pleiotropic factor, Uga3 has been described as a transcription factor specific for GABA metabolism. The analysis of the growth phenotype of mutants deficient in Dal81 or Uga3 under different conditions, suggested to us that these TFs might participate in more pathways than the described for them. We also found by coIP/WB that Uga3 and Dal81 interact even in the absence of GABA. We analysed the expression of several genes involved in the use of different amino acids in strains deficient in different TFs. We found that Uga3 regulate the induction of BAP2 gene, a gene involved in the branched amino acid catabolism. However, AGP1 and BAP3, involved in the same pathway are not regulated by Uga3. We also found that Dal81 is essential for the expression of genes of the Unfolded Protein Response (UPR) pathway. The main goal of the UPR is to restore the equilibrium between protein load and folding capacity of the endoplasmic reticulum; it clearly has both survival and cell death effects. So, Dal81 has an important physiological role, besides the regulation of amino acids catabolism.