Aitor Hierro Ayuela
Aitor Hierro
Ikerbasque Research Professor
Address: Bizkaia Science and Technology Park,
building 800, Derio (Bizkaia)
Membrane Trafficking Lab

Aitor Hierro obtained his Bachelor and Doctorate degrees in Biochemistry at the University of the Basque Country (UPV/EHU). As a PhD student, he examined the regulatory effects of phosphorylation of a nuclear chaperone and its interaction with histones. Between 2002 and 2007, he conducted his postdoctoral research at the National Institutes of Health (Bethesda, USA) under the supervision of Prof. James H. Hurley. During this period, his research was focused on the multivesicular-body sorting pathway. In 2008, Dr. Hierro joined CIC bioGUNE and began his independent research work on structural aspects of endosomal trafficking regulation and its role in physiological malfunction and disease. His research focuses on protein interactions regulating the higher levels of functionality. This research concentrates on the subtle interactions that regulate the transport of components between cell compartments and the role of miss-deliveries in the genesis of various diseases. One of the most important challenges in the trafficking field is deciphering the fidelity code by which cargo proteins are selectively recognized and delivered. Dr Hierro's laboratory has been focusing on the mechanisms and specific interactions during selective recruitment of cargo molecules from endosomes; He also investigates how the trafficking routes in this compartment are exploited by toxins and pathogens.

Dr. Hierro's lab uses a multidisciplinary approach including X-ray crystallography, electron microscopy, small angle X-ray scattering, biochemical reconstitution, ITC and SPR to uncover these higher order mechanisms in intracellular trafficking. The group fosters trans-disciplinary collaboration among world-class experts in computational simulations and cell biology for testing the mechanisms of the proposed structural models.

Living cells constantly recycle receptors, proteins and lipids with a direct impact on nutrient uptake, re-sensitisation to environmental signals, immune surveillance and waste management. Failure to recycle results in reduced signalling, oxidative stress, protein mislocalisation and aggregation, which are pathological hallmarks of many cardiovascular, cancer, and neurodegenerative diseases. Endosomes are key recycling compartments where the biosynthetic and endocytic pathways intersect. Here, the fate of sorting receptors is directly linked to their selective recruitment into tubulo-vesicular carriers. Our understanding of receptor recycling in a motif-dependent manner, the formation of such tubulo-vesicles and the functional components defining their architecture remains very limited. Retromer is a novel protein coat complex with a central role in multiple receptor-sorting events in the endosomes. Retromer combines receptor recruitment with membrane tubulation properties, but unlike other classical coats, it does so through a single-layer or “cage-free” organization.

This laboratory is interested in understanding how retromer components form a coat around tubulo-vesicles, how transmembrane receptors are selectively recruited to control essential cell processes, and how certain pathogens subvert and co-opt these interactions.