CCR chemokine receptor binding

Definition

Target type: molecularfunction

Binding to a CCR chemokine receptor. [GOC:ai]

CCR chemokine receptors are a family of G protein-coupled receptors (GPCRs) that play a crucial role in the immune system by mediating the chemotaxis of leukocytes. They bind to a specific class of chemokines, known as CC chemokines, which are small, secreted proteins that act as chemoattractants and activators of immune cells.

The molecular function of CCR chemokine receptor binding involves a series of steps:

1. **Chemokine Binding:** CC chemokines bind to the extracellular domain of CCR receptors, specifically to a conserved N-terminal region known as the chemokine binding domain. This binding event triggers a conformational change in the receptor, leading to activation.

2. **G Protein Coupling:** Upon chemokine binding, the activated CCR receptor interacts with a heterotrimeric G protein. This G protein consists of three subunits: alpha, beta, and gamma. The alpha subunit is responsible for signaling, while the beta and gamma subunits anchor the G protein to the plasma membrane.

3. **Signal Transduction:** The activated G protein alpha subunit dissociates from the beta and gamma subunits and interacts with downstream signaling molecules, such as phospholipase C (PLC). PLC hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol (DAG) and inositol triphosphate (IP3).

4. **Cellular Response:** DAG activates protein kinase C (PKC), which phosphorylates various intracellular proteins, leading to a variety of cellular responses, including:

- **Chemotaxis:** CCR receptor activation triggers the polymerization of actin filaments, leading to cell migration towards the chemokine gradient.

- **Cell Adhesion:** CCR receptors can also regulate cell adhesion by interacting with integrins, which are cell surface receptors that mediate cell-cell and cell-matrix interactions.

- **Cytokine Production:** CCR receptor activation can also stimulate the production of cytokines, which are signaling molecules that regulate immune responses.

- **Inflammation:** CCR receptors play a significant role in the inflammatory response by recruiting leukocytes to sites of inflammation.

5. **Desensitization:** To prevent excessive signaling, CCR receptors undergo a process called desensitization, where the receptors are internalized and degraded.

In summary, CCR chemokine receptor binding is a complex molecular process that involves the interaction of chemokines, receptors, G proteins, and downstream signaling molecules. This binding event triggers a cascade of signaling events, ultimately leading to a diverse array of cellular responses, including chemotaxis, cell adhesion, cytokine production, and inflammation. These processes are essential for the proper functioning of the immune system.'
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Proteins (1)

Compounds (4)