Fibrillin-3 (FBN3)

Fibrillin-3 is a large extracellular matrix glycoprotein coded by the FBN3 gene (chromosome 19p13.2) and is one of three human fibrillin family members[1][2][7][11]. Fibrillin-3 is a structural component of extracellular calcium-binding microfibrils (10-12 nm diameter), which provide long-term force-bearing support in connective tissues[1][7][10]. These microfibrils are present either independently or in association with elastin and are essential for the structural integrity of developing skeletal elements, skin, lung, kidney, muscle, and particularly reproductive organs, with a high expression noted in fetal development[1][2][4][12]. Fibrillin-3, like other fibrillins, interacts with fibronectin and contains EGF-like and TGFβ-binding protein-like domains and is highly conserved in humans but absent or nonfunctional in rodents[2][3][4]. Unlike FBN1 and FBN2, Fibrillin-3 has limited disease associations in humans but has been implicated through genetic studies in reproductive developmental roles and as a candidate gene for certain syndromic presentations—most notably polycystic ovary syndrome and Bardet–Biedl-like syndromes[2][4]. No approved drugs directly interact with Fibrillin-3, and it is not considered a classical druggable therapeutic target or receptor[1][7][10]. Key points: - Main extracellular matrix protein, but not an enzyme, receptor, or transporter[1][7]. - Highest expression is during embryonic and fetal development, especially in female reproductive organs and some neural tissues[2][4][12]. - No specific approved drugs or defined small-molecule ligands; no canonical biomarker roles. - Its clinical and biological significance is distinct from that of Fibrillin-1 (Marfan syndrome) and Fibrillin-2 (Beals syndrome)[6][7]. If a therapeutic context is needed, Fibrillin-3 might be a candidate for genetic, developmental, or reproductive biology research but is not an established drug target.

Other names

Fibrillin-3 C-terminal peptideKIAA1776ENSG00000142449