interleukin-2 receptor binding

Definition

Target type: molecularfunction

Binding to an interleukin-2 receptor. [GOC:ai]

Interleukin-2 receptor (IL-2R) binding is a crucial process in the immune system, facilitating the communication and activation of T cells. IL-2, a cytokine produced by activated T cells, plays a critical role in regulating immune responses. Binding of IL-2 to its receptor, a hetero-trimeric complex composed of IL-2Rα (CD25), IL-2Rβ (CD122), and γc (CD132), initiates a signaling cascade that leads to T cell proliferation, differentiation, and survival. The molecular function of IL-2R binding involves several key steps:

1. **Ligand Binding:** IL-2 binds to the IL-2Rα subunit, initiating the assembly of the complete receptor complex. The α subunit has a low affinity for IL-2, but its binding is essential for the recruitment of the β and γc subunits, which have higher affinity for IL-2.

2. **Receptor Dimerization:** Upon IL-2 binding, the IL-2Rα subunit associates with the IL-2Rβ and γc subunits, forming a stable trimeric complex. This dimerization brings the cytoplasmic domains of the β and γc subunits into close proximity, enabling downstream signaling events.

3. **Signal Transduction:** The cytoplasmic domains of the β and γc subunits contain Janus kinase (JAK) binding sites. Once the receptor complex is assembled, JAKs become activated and phosphorylate the receptor subunits.

4. **Activation of STAT Proteins:** Phosphorylation of the receptor subunits creates docking sites for signal transducer and activator of transcription (STAT) proteins. STAT proteins bind to the phosphorylated receptor and become phosphorylated themselves.

5. **Nuclear Translocation and Gene Expression:** Activated STAT proteins dimerize and translocate to the nucleus, where they bind to specific DNA sequences and regulate the transcription of genes involved in T cell proliferation, differentiation, and survival.

Overall, IL-2R binding is a complex process that involves multiple protein interactions and signaling pathways. The precise molecular mechanisms underlying these interactions and signaling events are still being investigated, but the understanding of IL-2R binding is essential for understanding immune regulation and developing therapeutic strategies for immune disorders.'
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Proteins (1)

Compounds (7)