Interview for Faculty Position

High resolution measurements of clathrin coats on the plasma membrane: What does it take to go live?

Saveez Saffarian

Harvard University

Proteins come together on the plasma membrane to create large complexes with distinct biological functions including among others: endocytosis, exocytosis, virus entry and virus egress. The protein complexes involved in these processes are in the range of 10-100 nm and have been extensively studied using electron microscopy, biochemistry and structural biology approaches. More recently the snapshot information generated using these methods have been complemented with live cell imaging of fluorescently tagged proteins. Live cell imaging provides the opportunity to obtain rates and probabilities that govern the formation of these complexes however its resolution is limited by diffraction.

In this talk I will focus on endocytosis which is driven by clathrin polymerization. Clathrin polymerizes on the plasma membrane and results in creation of a coated vesicle with the final size of ~100 nm. I will present the methodologies that we have developed including methods that allowed us to get high resolution measurements (~10 nm) of clathrin coats in live cells. The new tools enabled us to distinguish between clathrin coats with vastly different biological functions which are indistinguishable without the dynamic data.