Fluorogen-activating proteins provide tunable labeling densities for tracking FcεRI independent of IgE.

ABSTRACT: Crosslinking of IgE bound FcεRI on mast cells and basophils by multivalent antigen leads to degranulation and the release of key inflammatory mediators that stimulate the allergic response. Here, we present and characterize the use of fluorogen-activating proteins (FAPs) for single particle tracking of FcεRI to investigate how receptor mobility is influenced after IgE-induced changes in mast cell behavior. FAPs are genetically encoded tags that bind a fluorogen dye and increase its brightness upon binding up to 20,000-fold. We demonstrate that, by titrating fluorogen concentration, labeling densities from ensemble to single particle can be achieved, independent of expression level and without the need for wash steps or photobleaching. The FcεRI γ-subunit fused to a FAP (FAP-γ) provides, fo

SUBMITTER: Schwartz SL 

PROVIDER: S-EPMC4340345 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature