Ficolin

Ficolin
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Ficolins are a group of proteins that play a crucial role in the innate immune system. They are pattern recognition molecules that are involved in the activation of the complement system, particularly the lectin pathway. Ficolins are characterized by their ability to bind to carbohydrate structures on the surface of pathogens, leading to opsonization and clearance of these pathogens by the immune system.

Structure

Ficolins are oligomeric proteins composed of subunits that contain a collagen-like domain and a fibrinogen-like domain. The collagen-like domain is responsible for the oligomerization of the protein, while the fibrinogen-like domain is involved in the recognition and binding of carbohydrate structures. There are three main types of ficolins in humans: ficolin-1 (also known as M-ficolin), ficolin-2 (L-ficolin), and ficolin-3 (H-ficolin).

Function

Ficolins function as pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) on the surface of microorganisms. Upon binding to these structures, ficolins can activate the lectin pathway of the complement system. This activation involves the recruitment of mannose-binding lectin-associated serine proteases (MASPs), which subsequently cleave complement components C4 and C2, leading to the formation of the C3 convertase and the downstream activation of the complement cascade.

Clinical Significance

Alterations in ficolin levels or function can be associated with various diseases. For example, deficiencies in ficolin-2 have been linked to increased susceptibility to infections. Additionally, ficolins have been studied in the context of autoimmune diseases, where their role in modulating the immune response may contribute to disease pathogenesis.

Research

Ongoing research is focused on understanding the precise mechanisms by which ficolins recognize and bind to pathogens, as well as their interactions with other components of the immune system. There is also interest in exploring the potential of ficolins as therapeutic targets or biomarkers for infectious and inflammatory diseases.

Also see

• Complement system
• Lectin pathway
• Pattern recognition receptor
• Mannose-binding lectin

Ficolin
Identifiers
Symbol	?