Life at the cellular level must detect and respond correctly to diverse internal and external stimuli. The transcriptional regulatory system ensures the correct expression of specific genes at suitable times and plays a central role in controlling various biological processes: cell cycle, maintenance of intracellular metabolic and physiological balance, and cellular differentiation. Modifications in the regulatory system, such as different regulatory activity and specificity of transcription factors, are main sources for evolutionary adaptation and diversity. On the other hand, a considerable number of diseases result from a malfunctioning regulatory system.

Organisms can adapt their metabolic activity to environmental nutritional changes by modifying the level of gene expression of specific enzymes. The research in our laboratory focuses on the mechanisms that control gene expression. The main area of interest is to understand how the transcriptional and translational regulatory networks interact with other cellular components such as the metabolic system. This involves the analysis of the mechanisms through which the cell senses nutrient availability and transmits that information to the level of gene expression. It also involves looking at the transcription and translation control, which govern the expression of genes involved in carbohydrate metabolism in the Gram-positive model organism Bacillus subtilis.

Several lines of research are being followed. Currently we are carrying out two major research projects:

• Characterization of the AraR regulon comprising genes required for the extracellular degradation of polysaccharides, transport of oligomers and simple sugars, intracellular degradation and further catabolism.
• Elucidation of the regulatory mechanisms of hemicelullases and design of efficient enzymatic systems for economic degradation of the plant cell wall, by genetic and biochemical characterization of enzymatic consortia involved in the degradation of plant cell wall polysaccharides.