Research projects

The proteomic analysis of the interactions of human Nucleoside Transporter (hNT) proteins suggested the existence of protein complexes behaving as sensors of extracellular purine nucleosides. Our hypothesis was that these complexes can regulate nucleoside and nucleobase salvage pathways and the de novo biosynthetic purine nucleotide pathway in a coordinate manner. This type of fine tuning of nucleotide metabolism could be impaired in oncogenesis. Based upon this hypothesis the specific aims of the project were:

a) To demonstrate the existence of direct interactions, with functional implications, among selected enzymes of the purine salvage and de novo biosynthetic pathways.

b) To demonstrate that these protein complexes conform a cellular purine sensor likely to be altered during oncogenesis, thereby contributing to its associated metabolic reprogramming.

c) To incorporate within this sensor membrane nucleoside transporters and to establish the functional integrity of these complexes under conditions of metabolic stress.

During the last period of the project we have biochemically and functionally characterized a novel interacting protein of the broad selectivity nucleoside transporter hCNT3, previously identified using a MYTH (Membrane Yeast Two Hybrid) approach. This new member of the putative regulatory complex implicated in nucleotide metabolism is associated with the 1 Carbon Metabolism pathway, which is known to be essential for fueling de novo purine nucleotide biosynthesis. The functional relevance of this partnership has been preliminary studied using a metabolomics approach. The project funded by Fundación Ramón Areces is now being pursued within the framework of the main research lines of the Molecular Pharmacology and Experimental Therapeutics (MPET) group, at the Institute of Biomedicine of the University of Barcelona.