FCER1A

Case study 1: Alexandra M Greer, 2014

The high-affinity IgE receptor FcεRI is constitutively expressed in mast cells and basophils and is required for transmitting stimulatory signals upon engagement of IgE-bound allergens. FcεRI is also constitutively expressed in dendritic cells (DCs) and monocytes in humans; however, the specific functions of the FcεRI expressed by these cells are not completely understood.

In this study, FcεRI expressed by human blood DC antigen 1-positive (BDCA1+) DCs and monocytes, but not basophils, traffics to endolysosomal compartments under steady-state conditions. Furthermore, IgE bound to FcεRI on BDCA1+ DCs was rapidly endocytosed, transported to the lysosomes, and degraded in vitro. These findings strongly suggest that constitutive internalization of human FcεRI by DCs and monocytes distinctively contributes to serum IgE clearance.

Fig1. Gating strategy of human basophils and DCs, and histograms of surface FcεRI expression and surface IgE bound to the cells.

Fig2. FcεRIα maturation state in basophils and DCs.

Case study 2: David M Cauvi, 2006

The human high affinity IgE receptor (FcepsilonRI) is a central component of the allergic response and is expressed as either a trimeric alphagamma2 or tetrameric alphabetagamma2 complex. It has been previously described that the cytoplasmic domain (CD) of the alpha-chain carries a dilysine motif at positions -3/-7 from the C terminus that functions in intracellular retention prior to assembly with other FcepsilonRI subunits. In this report the researchers have further explored the role of the -3/-7 dilysine signal in controlling steady-state alpha-chain transport by mutational analysis.

They compared the transport properties of a series of alpha-chain cytoplasmic domain truncation mutants and performed alanine-scanning mutagenesis. Furthermore, co-mutation of the Lys(212)-Lys(216) residues with the -3/-7 dilysine signal produced a dramatic increase in alpha-chain surface expression.

Fig3. The intracellular expression of human wt FcϵRI α-chain and the -3/-7 dialanine mutant K226A/K230A in transfected COS-7 cells was visualized with an anti-FcϵRIα mAb 15-1 and anti-giantin Ab with co-localization shown in yellow in the merged images.

Fig4. HEK293 cells were transiently transfected with eitherαwt,αK210A,αK212A,αK212A/K216A, orαK212A/K216A/R213A/R215A and analyzed for cell-surface expression by flow cytometry.

Fig1. FcεRI signaling in allergic inflammation. (Hyein Jo, 2022)

Fig2. Upon FcεRI engagement by means of IgE loading followed by antigen stimulation, MCs release exosomes bearing receptors, IgE, and antigens that can cooperate with soluble multivalent antigens to amplify the inflammatory response. (Mario Lecce, 2020)

FCER1A involved in several pathways and played different roles in them. We selected most pathways FCER1A participated on our site, such as Sphingolipid signaling pathway, Phospholipase D signaling pathway, Fc epsilon RI signaling pathway, which may be useful for your reference. Also, other proteins which involved in the same pathway with FCER1A were listed below. Creative BioMart supplied nearly all the proteins listed, you can search them on our site.

FCER1A has several biochemical functions, for example, IgE binding, IgE receptor activity. Some of the functions are cooperated with other proteins, some of the functions could acted by FCER1A itself. We selected most functions FCER1A had, and list some proteins which have the same functions with FCER1A. You can find most of the proteins on our site.

FCER1A has direct interactions with proteins and molecules. Those interactions were detected by several methods such as yeast two hybrid, co-IP, pull-down and so on. We selected proteins and molecules interacted with FCER1A here. Most of them are supplied by our site. Hope this information will be useful for your research of FCER1A.

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