Formation of buds, pearls, and tubes in membranes

The formation of highly curved structures on the plasma membranes of cells is critical for trafficking. Buds form during endo and exocytosis, tubes and pearled structures also form during trafficking from internal organelles and in yeast endocytosis. In this work, using continuum models, I will elaborate on continuum models that can help us obtain insight into the parameter spaces necessary to obtain these shapes and particularly, how membrane tension can play a critical role in determining the outcome of these shapes. These models are based on the classic Helfrich energy with modifications to address the particular biophysical problem. Using clathrin-mediated endocytosis as an example, I will share results on how tension governs the formation of a vesicle and a tube. The contributions of spontaneous curvature and forces due to cytoskeleton interactions will also be discussed.  Since these shapes are motivated by experimental observations in cells and in vesicles, I will also talk about some of the challenges of using simple continuum models for such processes and room for advances in model development and computational schemes.