Barbara Korbei

Forschungsschwerpunkt

Due to accelerating climate change and the resulting rapid increase in extreme environmental conditions, the question of how plants can flexibly adapt to their constantly changing environment is a highly topical area of research. Plants, being sessile organisms, have evolved a plethora of mechanisms to be able to respond quickly and accurately to their surroundings. The plasma membrane serves as boundary between the inside and the outside of the cell and is densely packed with proteins that are responsible for sensing and transmitting stimuli. Plants thus have to be able to rapidly and accurately adjust not only the localization but also the amount of their plasma membrane proteins. This is organized by endosomal trafficking, which transports membrane proteins to and from their site of action. Here, the post-translational modification of plasma membrane proteins with the small protein ubiquitin is key in signaling their removal from the plasma membrane by endocytosis and further degradation in the vacuole. To understand the significance and the variety of roles played by this reversible modification, the function of ubiquitin receptors, which translate the ubiquitin signature into a cellular response, needs to be elucidated.
In this lab we try to unravel the function of the TOM1-like (TOL) protein family in the recognition and in initiating sorting to the vacuole of ubiquitinated plasma membrane proteins destined for degradation. The TOL proteins function in plants as multivalent ubiquitin receptors, governing ubiquitinated cargo delivery to the vacuole via the conserved Endosomal Sorting Complex Required for Transport (ESCRT) pathway.