receptorIgM

receptorIgM refers to the B cell receptor (BCR) in its IgM form. This transmembrane protein plays a crucial role in the adaptive immune system, acting as the first antibody isotype expressed by developing B cells. As a B cell matures, its BCR can switch to other isotypes like IgD, IgG, IgA, or IgE, but IgM remains the initial antigen-recognition molecule.

The receptorIgM is typically expressed as a monomer on the surface of immature and transitional B cells. Upon activation by an antigen, B cells can undergo proliferation and differentiation. In many cases, IgM then transitions to a pentameric structure, secreted by plasma cells, which is a more potent activator of the complement system. The pentameric form of secreted IgM is a hallmark of the early stages of a primary immune response.

The structure of receptorIgM consists of two identical heavy chains and two identical light chains, with a transmembrane domain that anchors it to the B cell membrane. Its extracellular domain binds to specific antigens, initiating intracellular signaling cascades that lead to B cell activation. This activation is essential for mounting an effective immune defense against pathogens.