BCR

BCR or B-cell receptor is a protein located on the surface of B cells, a type of white blood cell. The BCR is essential for the B cell to perform its role in the immune response. It allows B cells to bind to specific antigens, triggering the B cell to produce antibodies against the antigens.

Structure

The BCR is composed of two parts: a B-cell co-receptor complex and an antigen-binding fragment. The B-cell co-receptor complex is made up of three proteins: Ig-alpha, Ig-beta, and CD19. The antigen-binding fragment is made up of two identical heavy chains and two identical light chains, each with a variable region that can bind to a specific antigen.

Function

The primary function of the BCR is to bind to antigens. When the BCR binds to an antigen, it triggers a series of events inside the B cell. These events lead to the activation of the B cell, which then produces antibodies against the antigen. The antibodies are released into the bloodstream, where they can bind to the antigen and mark it for destruction by other cells of the immune system.

Clinical significance

Alterations in the BCR can lead to various diseases. For example, mutations in the genes that encode the BCR can lead to B-cell lymphoma, a type of cancer. In addition, the BCR is a target for several drugs used to treat autoimmune diseases, such as rheumatoid arthritis and multiple sclerosis.

See also

• Antibody
• B cell
• Immune system