FCRL5

FCRL5 (Fc Receptor-Like 5) is a protein that in humans is encoded by the FCRL5 gene. FCRL5 is a member of the Fc receptor-like family, which includes six members (FCRL1 to FCRL6) and is a group of immunoregulatory proteins with sequence homology to classical Fc receptors.

Function

FCRL5 is expressed on mature B cells and is thought to function in the regulation of the immune response. It is an immunoreceptor that binds to immunoglobulin molecules and can either inhibit or activate cell responses. The exact function of FCRL5 is still under investigation, but it is believed to play a role in autoimmune diseases and cancer.

Structure

The FCRL5 protein has a structure similar to other members of the Fc receptor-like family. It contains six immunoglobulin-like domains, a transmembrane domain, and two immunoreceptor tyrosine-based inhibition motifs (ITIMs). The ITIMs are thought to be involved in the inhibitory function of the receptor.

Clinical significance

Alterations in the expression of FCRL5 have been associated with various diseases. Overexpression of FCRL5 has been observed in chronic lymphocytic leukemia (CLL) and other B cell malignancies. It has also been associated with autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus (SLE).

Research

Research is ongoing to further understand the role of FCRL5 in the immune system and its potential as a therapeutic target in diseases such as cancer and autoimmune disorders.

File:Fcrl5 structure.png

Structure of the FCRL5 protein.

See also

• Fc receptor
• Immunoglobulin superfamily
• Chronic lymphocytic leukemia
• Rheumatoid arthritis
• Systemic lupus erythematosus