Clathrin phosphorylation is required for actin recruitment at sites of bacterial adhesion and internalization

Abstract

Bacterial pathogens recruit clathrin upon interaction with host surface receptors during infection. Here, using three different infection models, we observed that host–pathogen interactions induce tyrosine phosphorylation of clathrin heavy chain. This modification was critical for recruitment of actin at bacteria–host adhesion sites during bacterial internalization or pedestal formation. At the bacterial interface, clathrin assembled to form coated pits of conventional size. Because such structures cannot internalize large particles such as bacteria, we propose that during infection, clathrin-coated pits serve as platforms to initiate actin rearrangements at bacteria–host adhesion sites. We then showed that the clathrin–actin interdependency is initiated by Dab2 and depends on the presence of clathrin light chain and its actin-binding partner Hip1R, and that the fully assembled machinery can recruit Myosin VI. Together, our study highlights a physiological role for clathrin heavy chain phosphorylation and reinforces the increasingly recognized function of clathrin in actin cytoskeletal organization in mammalian cells.