Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

The Galione Lab has a paper published in The EMBO Journal showing that local Ca2+‐nanodomains formed by two‐pore channels (TPCs) on endo-lysosomes are shown to drive phagocytosis in macrophages. Moreover, different endo-lysosomal Ca2+ channels do different jobs at phagocytosis (extreme compartmentation).

Macrophages clear pathogens by phagocytosis and lysosomes that fuse with phagosomes are traditionally regarded as to a source of membranes and luminal degradative enzymes. Here, we reveal that endo‐lysosomes act as platforms for a new phagocytic signalling pathway in which FcγR activation recruits the second messenger NAADP and thereby promotes the opening of Ca2+‐permeable two‐pore channels (TPC s). Remarkably, phagocytosis is driven by these local endo‐lysosomal Ca2+ nanodomains rather than global cytoplasmic or ER Ca2+ signals. Motile endolysosomes contact nascent phagosomes to promote phagocytosis, whereas endo‐lysosome immobilization prevents it. We show that TPC ‐released Ca2+ rapidly activates calcineurin, which in turn dephosphorylates and activates the GTP ase dynamin‐2. Finally, we find that different endo‐lysosomal Ca2+ channels play diverse roles, with TPC s providing a universal phagocytic signal for a wide range of particles and TRPML 1 being only required for phagocytosis of large targets.

See the full paper here: https://www.embopress.org/doi/10.15252/embj.2019104058