Understanding plant endosomal sorting mechanisms and ESCRT function in plants

This project will analyze how plants regulate degradation of proteins at the cell surface to control cellular function. Cells remove proteins from their surface through a process called endocytosis during which cells internalize portions of their plasma membrane, including proteins, through the formation of endocytic vesicles. These vesicles fuse with cell compartments called endosomes that internalize the plasma membrane protein in endosomal vesicles and transport them to vacuoles for degradation.

This is a critical pathway as problems associated with endocytosis can often be lethal for the development of the plant. This project will investigate molecular and structural aspects of endosomal functions in different plant lineages to understand the key components and mechanisms of endosomal vesicle formation. This research will support the training of undergraduate and graduate students as well as postdoctoral researchers.

It will also provide fundamental insights into plant cell biology, relevant for agriculture, biotechnology, evolution, and bioenergy crops. In collaboration with the Emergency Technologies Hub at the Wisconsin Discovery Center, virtual reality material representing plant cells and organelles will be produced for outreach activities at the University of Wisconsin-Madison campus.

Endosomal sorting of membrane proteins regulates cell signaling but how endosomal vesicles form and sequester cargo is not well understood. The main goal of this project is to analyze the mechanisms by which budding sites at the endosomal membrane generate vesicles in Arabidopsis thaliana and to gain an evolutionary and functional perspective of different patterns of budding activity across lineages, from basal to flowering plants.

This project will undertake a comprehensive approach (genetics, imaging, biochemistry) to investigate the mechanistic roles of a group of plant-specific proteins that bind endosomal membranes and to analyze structural features of endosomes in different plant lineages related to the evolution of endosomal vesiculation within plants.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.