Seminar

Mechanisms underlying endosomal transport

Aitor Hierro, PhD

Living cells are constantly moving material as part of their inherent activity and environmental interactions. The endosomal network is a mayor hub in protein trafficking. It receives a large number of transmembrane proteins, receptors and ligands, termed cargo, from the secretory and endocytic pathways which then are routed to the lysosome for degradation or recycled for re-use. Protein recycling has a direct impact on cellular homeostasis and is altered with aging. Of the cargo molecules delivered to endosomes, about two-thirds are rescued from degradation and recycled for reuse. Each recycling pathway utilizes distinct sets of molecular machinery to transport channels and receptors involved in a wide range of physiological processes such as nutrient intake, cell signaling, polarized transport, cell differentiation, immune response and nerve transmission. These endosomal assemblies have a large number of components regulating the formation of specific exit routes. Spatio-temporal control of these events not only is essential for general proteostasis, but also is subverted by numerous pathogens. In this talk I will present our recent work on the molecular mechanisms for recognition, packaging and sorting of integral membrane proteins into specific membrane-coated structures