Muñoz Sebastián A, Gulias Juan F, Valencia-Guillén Jenniffer, Correa-García Susana, Bermúdez-Moretti Mariana
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina.
Microbiology (Reading). 2020 Jan;166(1):85-92. doi: 10.1099/mic.0.000863.
Gene regulation in yeast occurs at the transcription level, i.e. the basal level of expression is very low and increased transcription requires gene-specific transcription factors allowing the recruitment of basal transcriptional machinery. gene encodes the permease responsible for most uptake of leucine, valine and isoleucine, amino acids that this yeast can use as nitrogen sources. Moreover, expression is known to be induced by the presence of amino acids such as leucine. In this context, the results presented in this paper show that is an inducible gene in the presence of nitrogen-non-preferred source proline but exhibits high constitutive non-inducible expression in nitrogen-preferred source ammonium. expression is regulated by the SPS sensor system and transcription factors Leu3, Gcn4 and Dal81. This can be achieved or not through a direct binding to the promoter depending on the quality of the nitrogen source. We further demonstrate here that an interaction occurs between Uga3 ‒ the transcriptional activator responsible for γ-aminobutyric acid (GABA)-dependent induction of the GABA genes ‒ and the regulatory region of the gene, which leads to an increase in transcription.
酵母中的基因调控发生在转录水平，即基础表达水平非常低，转录增加需要基因特异性转录因子，以允许募集基础转录机制。该基因编码负责大部分亮氨酸、缬氨酸和异亮氨酸摄取的通透酶，这些氨基酸是这种酵母可以用作氮源的物质。此外，已知该基因的表达受亮氨酸等氨基酸的诱导。在此背景下，本文呈现的结果表明，在氮非首选源脯氨酸存在的情况下，该基因是一个可诱导基因，但在氮首选源铵中表现出高组成性非诱导表达。该基因的表达受SPS传感器系统以及转录因子Leu3、Gcn4和Dal81的调控。这可以通过直接结合启动子来实现，具体取决于氮源的质量。我们在此进一步证明，负责γ-氨基丁酸（GABA）依赖性诱导GABA基因的转录激活因子Uga3与该基因的调控区域之间发生相互作用，这导致该基因转录增加。
