low-affinity IgE receptor activity

Definition

Target type: molecularfunction

Combining with low affinity with an immunoglobulin of the IgE isotype via the Fc region, and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity. [GOC:add, GOC:signaling, ISBN:0781735149]

Low-affinity IgE receptor activity, also known as CD23 or FcepsilonRII, is a type II transmembrane protein that serves as a receptor for IgE antibodies. It plays a crucial role in the regulation of IgE-mediated immune responses and allergic reactions.

The molecular function of low-affinity IgE receptor activity is multifaceted, involving several key processes:

1. **IgE Binding:** CD23 binds to the Fc region of IgE antibodies with low affinity, facilitating IgE capture and aggregation. This binding event triggers downstream signaling pathways.
2. **IgE Presentation:** CD23 acts as an IgE-presenting molecule, presenting IgE to other immune cells, such as B cells and mast cells. This presentation process promotes IgE sensitization and subsequent immune responses.
3. **Signal Transduction:** Upon IgE binding, CD23 initiates intracellular signaling cascades through its association with various intracellular signaling molecules. These signaling pathways contribute to the activation and regulation of immune cells.
4. **Modulation of IgE Levels:** CD23 can regulate the production and degradation of IgE. It can either enhance or suppress IgE synthesis, depending on the context and the specific signaling pathways activated.
5. **Immunomodulation:** CD23 plays a role in modulating the immune response by influencing the activation and differentiation of immune cells, such as B cells, mast cells, and eosinophils.

The molecular function of low-affinity IgE receptor activity is complex and highly regulated. It involves a delicate balance between IgE binding, signaling, and immunomodulatory functions. Disruptions in CD23 function can contribute to the development of allergic disorders and other immune system dysfunctions.'
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Proteins (1)

Compounds (3)