Endocytosis and signalling
Endocytosis is driven by vesicle formation at the plasma membrane and follows the same routes as uptake of nutrients, extracellular medium, membranes and cell surface proteins. It is a major entry gate for pathogens into cells and serves important functions in anti-microbial and anti-viral responses by the host immune system. Incoming adenovirus type 2 or 5 enter by clathrin-mediated endocytosis and activate clathrin-independent macropinocytosis. Both of these endocytic processes require the viral coreceptor alpha v integrin. Macropinocytosis is not essential for viral uptake but macropinosomal contents of infected cells are released into the cytosol, indicating that adenovirus regulates the cellular machinery controlling endosomal leakiness. This correlates with endosomal exit of virus and infection. We are analyzing the mechanisms of endosomal lysis triggered by adenovirus.
|Image 2a: Clathrin-mediated endocytosis of adenovirus serotype 2 triggers macropinocytosis and macropinosomal lysis.||Image 2b: The escape of phagosomal adenovirus targeted to the Fc-gamma receptor of hematopoietic cells requires late stages of clathrin-coated pit formation.|