coreseptor

A coreceptor is a cell surface protein that assists another receptor in binding to its ligand and triggering a downstream cellular response. Coreceptors do not bind to the ligand independently but are required for high-affinity binding and signal transduction. They often work in conjunction with primary receptors, amplifying or modulating the signal. A well-known example is the CD4 molecule on T helper cells, which acts as a coreceptor for the T cell receptor, enhancing its interaction with antigen-presenting cells. Other examples include CD8, another T cell coreceptor, and various immunoglobulinlike molecules involved in immune cell activation. The interaction between a coreceptor and its primary receptor can be crucial for the specificity and strength of cellular communication. Dysregulation of coreceptor function can lead to various immune deficiencies or autoimmune diseases.