ICAM3

ICAM3 (InterCellular Adhesion Molecule 3) is a protein that in humans is encoded by the ICAM3 gene. It is a member of the intercellular adhesion molecule (ICAM) family of immunoglobulin superfamily. ICAM3 plays a crucial role in the immune system, particularly in the process of leukocyte adhesion and migration.

Structure

ICAM3 is a type I transmembrane glycoprotein with a molecular weight of approximately 110 kDa. It consists of five immunoglobulin-like domains, a transmembrane region, and a short cytoplasmic tail. The extracellular portion of ICAM3 contains binding sites for lymphocyte function-associated antigen 1 (LFA-1), a protein involved in leukocyte adhesion.

Function

ICAM3 is primarily expressed on leukocytes and is involved in various immune responses. It facilitates the adhesion and migration of leukocytes by interacting with LFA-1. This interaction is crucial for the immune response, as it allows leukocytes to travel to the site of infection or inflammation.

ICAM3 also plays a role in T cell activation. It is involved in the initial interaction between T cells and dendritic cells, which is a critical step in the immune response.

Clinical Significance

Alterations in the expression or function of ICAM3 can lead to various health conditions. For example, reduced levels of ICAM3 have been associated with rheumatoid arthritis, a chronic inflammatory disorder. Additionally, ICAM3 has been implicated in the progression of certain types of cancer, as it can promote tumor cell migration and invasion.

See Also

• Intercellular adhesion molecule
• Lymphocyte function-associated antigen 1
• T cell
• Dendritic cell