Alicia González Manjarrez

Intereses de Investigación

MICROBIOLOGY: NITROGEN METABOLISM IN YEAST. USING GENETICS AND MOLECULAR BIOLOGY

Trayectoria Profesional

Investigadora Titular C

Formación Académica

Doctorado en Investigación Biomédica Básica, IBB UACPyP, Universidad NAcional Autónoma de México, México ()

Líneas de Investigación

Transcriptional regulation of the genes involved in glutamate biosynthesis in Saccharomyces cerevisiae: Our group has been interested in the study of the genes and enzymes that play a role in ammonium assimilation and glutamate biosynthesis in S. cerevisiae. As well as other microorganisms, this yeast has two pathways to assimilate ammonium and biosynthesize glutamate: the NADP-dependent glutamate dehydrogenase (NADP-GDH) and the glutamine synthetase (GS) (GLN1)-glutamate synthase (GOGAT) (GLT1) pathway. Our group found that S. cerevisiae has two different genes: GDH1 and GDH3, encoding two different NADP-GDH isozymes. So this is the first organism to have three enzymes involved in glutamate biosynthesis. We have purified and characterised the enzymes encoded by each one of these three genes (GLT1, GDH3 and GDH1). We are currently studying the transcriptional regulation and chromatin organisation of GDH1 and GDH3. In regard to GLT1 we have studied its transcriptional regulation and are now involved in the study of the chromatin rearrangements of its promoter during repression and induced conditions. Since we found that GLT1 expression is regulated by the acetylase encoded by GCN5, we are also determining the acetylation sites in the promoter, by chromatin immunoprecipitation with antibodies against acetylated and non-acetylated histones. All of these strategies are aimed to establish the alternative role of each one of these pathways in different physiological conditions and to understand the role of chromatin remodelling in gene expression. We have also undertaken the study of glutamate biosynthesis in other yeasts, like Kluyveromyces lactis. In this regard, we have obtained mutants that allowed us to establish that this yeast has two pathways for glutamate biosyntesis: NADP-GDH and GS-GOGAT and that double mutants in GDH1 and GLT1 are full glutamate auxotrophs. We are currently involved in the cloning of the genes encoding the above mentioned enzymes.

Integrantes del Laboratorio

Juan Carlos Campero Basaldua

Estudiantes