Collagen, type IV, alpha 3 explained

Collagen alpha-3(IV) chain is a protein that in humans is encoded by the COL4A3 gene.^[1]

Type IV collagen, the major structural component of basement membranes, is a multimeric protein composed of 3 alpha subunits; this gene encodes the alpha 3 subunit. These subunits are encoded by 6 different genes, alpha 1 through alpha 6, each of which can form a triple helix structure with 2 other subunits to form type IV collagen. In Goodpasture's syndrome, autoantibodies bind to the collagen molecules in the basement membranes of alveoli and glomeruli. The epitopes that elicit these autoantibodies are localized largely to the non-collagenous C-terminal domain of the protein. A specific kinase phosphorylates amino acids in this same C-terminal region and the expression of this kinase is upregulated during pathogenesis. There are multiple alternate transcripts that appear to be unique to this human alpha 3 gene and alternate splicing is restricted to the six exons that encode this C-terminal domain. This gene is also linked to an autosomal recessive form of Alport syndrome. The mutations contributing to this syndrome are also located within the exons that encode this C-terminal region. Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter. Some exons of this gene are interspersed with exons of an uncharacterized gene which is on the opposite strand.^[2]

Disease Database

LOVD Alport gene variant databases (COL4A3, COL4A4, COL4A5)

Further reading

• Hinek A . Nature and the multiple functions of the 67-kD elastin-/laminin binding protein. . Cell Adhes. Commun. . 2 . 3 . 185–93 . 1995 . 7827955 . 10.3109/15419069409004436 .
• Ständer M, Naumann U, Wick W, Weller M . Transforming growth factor-beta and p-21: multiple molecular targets of decorin-mediated suppression of neoplastic growth. . Cell Tissue Res. . 296 . 2 . 221–7 . 1999 . 10382266 . 10.1007/s004410051283 . 20282995 .
• Kurpakus Wheater M, Kernacki KA, Hazlett LD . Corneal cell proteins and ocular surface pathology. . Biotechnic & Histochemistry . 74 . 3 . 146–59 . 1999 . 10416788 . 10.3109/10520299909047967.
• Pescucci C, Longo I, Bruttini M . Type-IV collagen related diseases. . J. Nephrol. . 16 . 2 . 314–6 . 2003 . 12768082 . etal.
• Torra R, Tazón-Vega B, Ars E, Ballarín J . Collagen type IV (alpha3-alpha4) nephropathy: from isolated haematuria to renal failure. . Nephrol. Dial. Transplant. . 19 . 10 . 2429–32 . 2005 . 15280517 . 10.1093/ndt/gfh435 . free .
• Rana K, Wang YY, Buzza M . The genetics of thin basement membrane nephropathy. . Semin. Nephrol. . 25 . 3 . 163–70 . 2005 . 15880327 . 10.1016/j.semnephrol.2005.01.008 . etal.
• Maziers N, Dahan K, Pirson Y . [From Alport syndrome to benign familial hematuria: clinical and genetic aspect] . Nephrol. Ther. . 1 . 2 . 90–100 . 2006 . 16895672 . 10.1016/j.nephro.2005.03.005 .
• Ghebrehiwet B, Peerschke EI, Hong Y . Short amino acid sequences derived from C1q receptor (C1q-R) show homology with the alpha chains of fibronectin and vitronectin receptors and collagen type IV. . J. Leukoc. Biol. . 51 . 6 . 546–56 . 1992 . 1377218 . 10.1002/jlb.51.6.546. 1214598 . etal.
• Quinones S, Bernal D, García-Sogo M . Exon/intron structure of the human alpha 3(IV) gene encompassing the Goodpasture antigen (alpha 3(IV)NC1). Identification of a potentially antigenic region at the triple helix/NC1 domain junction. . J. Biol. Chem. . 267 . 28 . 19780–4 . 1992 . 10.1016/S0021-9258(19)88621-0 . 1400291 . etal. free .
• Gupta S, Batchu RB, Datta K . Purification, partial characterization of rat kidney hyaluronic acid binding protein and its localization on the cell surface. . Eur. J. Cell Biol. . 56 . 1 . 58–67 . 1992 . 1724753 .
• Morrison KE, Mariyama M, Yang-Feng TL, Reeders ST . Sequence and localization of a partial cDNA encoding the human alpha 3 chain of type IV collagen. . Am. J. Hum. Genet. . 49 . 3 . 545–54 . 1991 . 1882840 . 1683122.
• Hernandez MR, Igoe F, Neufeld AH . Extracellular matrix of the human optic nerve head. . Am. J. Ophthalmol. . 102 . 2 . 139–48 . 1986 . 2426947 . 10.1016/0002-9394(86)90134-0 .
• Griffin CA, Emanuel BS, Hansen JR . Human collagen genes encoding basement membrane alpha 1 (IV) and alpha 2 (IV) chains map to the distal long arm of chromosome 13. . Proc. Natl. Acad. Sci. U.S.A. . 84 . 2 . 512–6 . 1987 . 3025878 . 10.1073/pnas.84.2.512 . 304239. etal. free . 1987PNAS...84..512G .
• Murata K, Motayama T, Kotake C . Collagen types in various layers of the human aorta and their changes with the atherosclerotic process. . Atherosclerosis . 60 . 3 . 251–62 . 1986 . 3089234 . 10.1016/0021-9150(86)90172-3 .
• Glant TT, Hadházy C, Mikecz K, Sipos A . Appearance and persistence of fibronectin in cartilage. Specific interaction of fibronectin with collagen type II. . Histochemistry . 82 . 2 . 149–58 . 1985 . 3997552 . 10.1007/bf00708199. 19401258 .
• Uscanga L, Kennedy RH, Stocker S . Immunolocalization of collagen types, laminin and fibronectin in the normal human pancreas. . Digestion . 30 . 3 . 158–64 . 1984 . 6389236 . 10.1159/000199100 . etal.
• Sundarraj N, Willson J . Monoclonal antibody to human basement membrane collagen type IV. . Immunology . 47 . 1 . 133–40 . 1982 . 6811420 . 1555500.
• Hahn E, Wick G, Pencev D, Timpl R . Distribution of basement membrane proteins in normal and fibrotic human liver: collagen type IV, laminin, and fibronectin. . Gut . 21 . 1 . 63–71 . 1980 . 6988303 . 10.1136/gut.21.1.63 . 1419572.
• Singhal PC, Sharma P, Garg P . HIV-1 gp160 protein-macrophage interactions modulate mesangial cell proliferation and matrix synthesis. . Am. J. Pathol. . 147 . 6 . 1780–9 . 1996 . 7495302 . 1869951.

Notes and References

1. Turner N, Mason PJ, Brown R, Fox M, Povey S, Rees A, Pusey CD . Molecular cloning of the human Goodpasture antigen demonstrates it to be the alpha 3 chain of type IV collagen . J Clin Invest . 89 . 2 . 592–601 . Mar 1992 . 1737849 . 442892 . 10.1172/JCI115625 .
2. Web site: Entrez Gene: COL4A3 collagen, type IV, alpha 3 (Goodpasture antigen).