coreceptor activity

Definition

Target type: molecularfunction

Combining with an extracellular or intracellular messenger, and in cooperation with a nearby primary receptor, initiating a change in cell activity. [GOC:go_curators]

Coreceptor activity is a molecular function that describes the ability of a molecule, typically a protein, to bind to another molecule, often a ligand, and facilitate or modulate the activity of a third molecule, usually a receptor. This process is often crucial for cellular signaling pathways and can influence a wide range of biological processes.

Here's a more detailed breakdown of coreceptor activity:

* **Binding:** Coreceptors bind to specific ligands, which can be small molecules, peptides, or even other proteins. This binding event often triggers a conformational change in the coreceptor, exposing or altering its interaction sites.
* **Modulation of Receptor Activity:** Coreceptors can influence the activity of receptors in various ways. They can:
* **Enhance receptor signaling:** By binding to the receptor, coreceptors can increase its affinity for the ligand, stabilize the receptor in an active conformation, or recruit downstream signaling molecules.
* **Inhibit receptor signaling:** Coreceptors can also suppress receptor signaling by blocking ligand binding, inducing receptor internalization, or preventing the recruitment of downstream signaling molecules.
* **Alter receptor specificity:** Coreceptors can change the type of ligand a receptor binds to, thereby expanding its functional repertoire.
* **Cellular Context:** The role of coreceptors is often highly context-dependent. Their expression levels, interactions with other proteins, and cellular localization can all influence their activity.
* **Examples:** Coreceptors play essential roles in many biological processes, including:
* **Immune response:** Coreceptors like CD4 and CD8 are crucial for T cell activation and differentiation.
* **Signal transduction:** Coreceptors like G protein-coupled receptors (GPCRs) mediate the activity of a wide range of signaling pathways.
* **Viral entry:** Coreceptors like CCR5 and CXCR4 are used by HIV to enter cells.

Overall, coreceptor activity is a complex process that involves interactions between multiple molecules and can have a profound impact on cellular function.'
"

Proteins (19)

Compounds (927)