Rab5a Regulates Surface Expression of Fc[epsilon]RI and Functional Activation in Mast Cells

Surface expression levels of high-affinity immunoglobulin E (IgE) receptors (Fc[straight epsilon]RI) on mast cells are regulated by constitutive internalization from the plasma membrane, which is thought to be an important determinant of Fc[straight epsilon]RI-mediated signaling potential. However,...

Full description

Saved in:
Bibliographic Details
Published in:Biological & pharmaceutical bulletin 2011-05, Vol.34 (5), p.760
Main Authors: Kageyama-Yahara, Natsuko, Suehiro, Yoko, Yamamoto, Takeshi, Kadowaki, Makoto
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Surface expression levels of high-affinity immunoglobulin E (IgE) receptors (Fc[straight epsilon]RI) on mast cells are regulated by constitutive internalization from the plasma membrane, which is thought to be an important determinant of Fc[straight epsilon]RI-mediated signaling potential. However, molecular mechanism of Fc[straight epsilon]RI trafficking has remained poorly understood. Rab proteins are small guanosine 5'-triphosphatases (GTPases) involved in the regulation of membrane traffic. In particular, Rab5 has been shown to regulate transport in the early endocytic pathway, whereas it is not known whether the Fc[straight epsilon]RI surface expression levels are regulated by Rab5. In this study, we investigated the role of individual Rab5 isoforms in mast cells by small interfering RNA knockdown method. Our results demonstrate that Rab5a knockdown enhanced Fc[straight epsilon]RI-dependent mast cell activation and upregulated Fc[straight epsilon]RI surface expression in its steady state. In contrast, Rab5c knockdown caused suppression of the activation. These findings revealed modulatory and individual roles of Rab5 isoforms in mast cell functions.
ISSN:0918-6158
1347-5215