Abstract
In addition to initiating signaling cascades leading to mast cell mediator release, aggregation of the high affinity IgE receptor (FcεRI) leads to rapid internalization of the cross-linked receptor. However, little is known about the trafficking of the internalized FcεRI. Here we demonstrate that in RBL-2H3 cells, aggregated FcεRI appears in the early endosomal antigen 1 (EEA1+) domains of the early endosomes within 15 min after ligation. Minimal co-localization of FcεRI with Rab5 was observed by 30 min, followed by its appearance in the Rab7+ late endosomes and lysosomes at later time points. During endosomal sorting, FcεRIα and γ subunits remain associated. In Syk-deficient RBL-2H3 cells, the rate of transport to lysosomes is markedly increased. Taken together, our data demonstrate time-dependent sorting of aggregated FcεRI within the endosomal-lysosomal network, and that Syk may play an essential role in regulating the trafficking and retention of FcεRI in endosomes.
Original language | English |
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Pages (from-to) | 793-802 |
Number of pages | 10 |
Journal | Molecular Immunology |
Volume | 46 |
Issue number | 5 |
DOIs | |
State | Published - Feb 2009 |
Externally published | Yes |
Keywords
- Co-localization
- Endosomes
- FcεRI
- Syk