Immunoglobuliiniperhe

Immunoglobuliiniperhe, commonly known as the immunoglobulin superfamily (IgSF), is a large group of structurally related proteins that play crucial roles in the immune system and other biological processes. These proteins are characterized by the presence of one or more immunoglobulin domains, which are conserved structural units of approximately 70-110 amino acids folded into a beta-sheet structure. This domain structure is fundamental to their function in molecular recognition.

The most well-known members of the immunoglobulin superfamily are the antibodies, also known as immunoglobulins. Antibodies are secreted proteins produced by B cells that are essential for adaptive immunity. They recognize and bind to specific antigens, marking them for destruction or neutralization by other components of the immune system. However, the IgSF extends far beyond antibodies. It includes a diverse array of cell surface receptors, adhesion molecules, and secreted proteins involved in cell-cell interactions, signal transduction, and immune cell trafficking.

Examples of non-antibody IgSF members include the T cell receptor (TCR), which recognizes antigens presented by MHC molecules on antigen-presenting cells, and the B cell receptor (BCR), which is a membrane-bound antibody that initiates B cell activation. Other important members include molecules like CD4 and CD8, which are co-receptors for the TCR, and various adhesion molecules such as ICAMs (intercellular adhesion molecules) and VCAMs (vascular cell adhesion molecules), which mediate cell adhesion and migration. The broad distribution and diverse functions of IgSF proteins highlight their central importance in maintaining physiological homeostasis and responding to pathogens.