Valarie A. Barr

Abstract We describe the first cases of germline biallelic null mutations in ARPC5, part of the Arp2/3 actin nucleator complex, in two unrelated patients presenting with recurrent and severe infections, early-onset autoimmunity, inflammation, and dysmorphisms. This defect compromises multiple cell lineages and functions, and when protein expression is reestablished in-vitro, the Arp2/3 complex conformation and functions are rescued.

Multicolour photoactivated localization microscopy (MC-PALM) imaging holds the promise of resolving the structure and composition of signalling complexes in molecular detail in intact cells and at nanometre resolution. However, at present, the spectral emissions of PA proteins that are used in PALM typically fall into either a green (GFP-like, 515–530 nm) or a red (RFP-like, 550–600 nm) channel (for example, refs 15, 16).