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PhD Discussions Session: Verónica Hortigüela & Anna Crespo
Friday, July 10, 2015 @ 10:00 am–11:00 am
Developing a platform for receptor clustering studiesVerónica Hortigüela, Biomimetic systems for cell engineering group
Receptors are signaling units that usually require interactions and associations with other molecules in complexes to trigger a signaling pathway. This process is known as receptor clustering and comes typically along with a simultaneous ligand clustering underneath the cell membrane. We have developed a strategy to precisely control the ligand distribution on a substrate at the nanoscale to study in detail receptor clustering processes. Herein we present a tunable platform based on self-assembled di-block copolymers that tend to segregate into nanostructures. Di-block copolymers are confined to a thin film providing a template for ligand patterning.
Ribonucleotide Reductase anaerobic enzymes are essential for biofilm formation of Pseudomonas aeruginosaAnna Crespo, Bacterial infections: antimicrobial therapies group
Most chronic infections in humans are caused by communities of microorganisms living in organized structures, known as biofilms. Biofilm-related infections, such as pneumonia (in patients suffering for cystic fibrosis or chronic obstructive pulmonary disease –COPD-) and catheter-associated infections, affect millions of people in the developed world.
Cell clusters in biofilms are characterized by presenting, in its extracellular polymeric matrix, gradients of oxygen, nutrients and metabolic waste products. The so-formed chemical heterogeneity (e.g., the presence of anoxic areas) leads to the appearance of different metabolic activities.
Pseudomonas aeruginosa has been used as a model bacterium for biofilm research; it causes biofilm-related chronic infections and presents high metabolic versatility, together with an extreme antibiotic resistance.
In this work we have studied P. aeruginosa, focusing in an essential enzyme for its growth, Ribonucleotide Reductase (RNR). Ribonucleotide Reductases catalyse the reduction of ribonucleotides (NTPs) to deoxyribonucleotides (dNTPs), thereby providing the building blocks for DNA synthesis. There are three different RNR classes, named class I, class II and class III, which are, respectively, oxygen-dependent, oxygen-independent and oxygen-sensitive. The last two ones, essential for anaerobic growth in Pseudomonas aeruginosa, have been proved to be necessary for biofilm formation, and therefore putative targets for new therapies against P. aeruginosa chronic infections.