Swa2p-dependent clathrin dynamics is critical for Flo11p processing and 'Mat' formation in the yeast Saccharomyces cerevisiae

The yeast Saccharomyces cerevisiae is able to form complex multicellular structures called mats on low-density agar Petri plates. Mat formation strictly depends on Flo11p, a cell surface mannoprotein that mediates the adhesion of yeast cells to the agar surface. Here, we show that Swa2p, an auxilin ortholog required for clathrin-coated vesicle uncoating, is strictly required for biofilm formation. We show that the maturation and cellular levels of Flo11p are affected in Δswa2 cells, yet without compromising invasive growth. Both the TPR and J-domains of Swa2p, but not its clathrin-binding and ubiquitin-association motifs, are required for its function in Flo11p processing.