Clathrin and Polarity

Clathrin consists of three clathrin heavy chains and three clathrin light chains that assemble into a clathrin triskelion. This triskelion  constitutes the backbone of clathrin-coated vesicles that mediate endocytosis.

 

Clathrin-mediated endocytosis is a fundamental uptake pathway in eukaryotic cells and is involved in several important processes for the cells, such as turnover of proteins and lipids in the plasma membrane, cell signaling, nutrient uptake, and cell motility.

Adapted from Fotin et al., 2004

In the Boulant Lab, we are interested in how clathrin regulates cellular polarity. Particularly, we are investigating how clathrin establishes and maintains apical and basolateral polarity in epithelial cells and how clathrin participates in ventral/dorsal and leading/trailing edge polarity in migrating cells.

Dynamics of ventral clathin pits and plaques

TEM rotary shadowing of clathrin

Clathrin observed by TEM

U373 AP2-GFP Zyxin-mcherry pFN-A647 on cFN 2-1

Clathrin and Zyxin

U373 AP2-GFP Lifeact-cherry

Clathrin and actin network

We are investigating the molecular mechanisms and dynamic  formation/turnover of canonical clathrin-coated pits and of long-lived clathrin plaques at the plasma membrane. We are addressing how the nature (size, shape,etc...) of cargo influences coat formation.

Role of clathrin in migrating cells

We are interested in how clathrin-mediated endocytosis participates in cell migration by regulating the turnover of focal adhesion. We use micro patterning approaches to control both the  shape and composition of the extracellular matrix (ECM) on which cells migrate. We employ traction force microscopy to address how clathrin arrays participate in interaction with the ECM

Clathrin structures and microtubules

Clathrin and focal adhesion

Microtubule network

Traction force microscopy

We use a multidisciplinary approach ranging from live cell fluorescence microscopy, super-resolution microscopy, correlative light electron microscopy, biophysics and genetic manipulation/ablation.

 

U373 AP2-GFP Lifeact-cherry

Clathrin and actin network