| Structural highlights
Disease
CFAH_HUMAN Genetic variations in CFH are associated with basal laminar drusen (BLD) [MIM:126700; also known as drusen of Bruch membrane or cuticular drusen or grouped early adult-onset drusen. Drusen are extracellular deposits that accumulate below the retinal pigment epithelium on Bruch membrane. Basal laminar drusen refers to an early adult-onset drusen phenotype that shows a pattern of uniform small, slightly raised yellow subretinal nodules randomly scattered in the macula. In later stages, these drusen often become more numerous, with clustered groups of drusen scattered throughout the retina. In time these small basal laminar drusen may expand and ultimately lead to a serous pigment epithelial detachment of the macula that may result in vision loss. Defects in CFH are the cause of complement factor H deficiency (CFHD) [MIM:609814. A disorder that can manifest as several different phenotypes, including asymptomatic, recurrent bacterial infections, and renal failure. Laboratory features usually include decreased serum levels of factor H, complement component C3, and a decrease in other terminal complement components, indicating activation of the alternative complement pathway. It is associated with a number of renal diseases with variable clinical presentation and progression, including membranoproliferative glomerulonephritis and atypical hemolytic uremic syndrome.[1] [2] [3] [4] [5] [6] [7] [8] Defects in CFH are a cause of susceptibility to hemolytic uremic syndrome atypical type 1 (AHUS1) [MIM:235400. An atypical form of hemolytic uremic syndrome. It is a complex genetic disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, renal failure and absence of episodes of enterocolitis and diarrhea. In contrast to typical hemolytic uremic syndrome, atypical forms have a poorer prognosis, with higher death rates and frequent progression to end-stage renal disease. Note=Susceptibility to the development of atypical hemolytic uremic syndrome can be conferred by mutations in various components of or regulatory factors in the complement cascade system. Other genes may play a role in modifying the phenotype.[9] [10] [11] [12] [13] [14] [15] [16] Genetic variation in CFH is associated with age-related macular degeneration type 4 (ARMD4) [MIM:610698. ARMD is a multifactorial eye disease and the most common cause of irreversible vision loss in the developed world. In most patients, the disease is manifest as ophthalmoscopically visible yellowish accumulations of protein and lipid (known as drusen) that lie beneath the retinal pigment epithelium and within an elastin-containing structure known as Bruch membrane.[17]
Function
CFAH_HUMAN Factor H functions as a cofactor in the inactivation of C3b by factor I and also increases the rate of dissociation of the C3bBb complex (C3 convertase) and the (C3b)NBB complex (C5 convertase) in the alternative complement pathway.
Publication Abstract from PubMed
Factor H (FH) is a soluble regulator of the human complement system affording protection to host tissues. It selectively inhibits amplification of C3b, the activation-specific fragment of the abundant complement component C3, in fluid phase and on self-surfaces and accelerates the decay of the alternative pathway C3 convertase, C3bBb. We have determined the crystal structure of the three carboxyl-terminal complement control protein (CCP) modules of FH (FH18-20) that bind to C3b, and which additionally recognize polyanionic markers specific to self-surfaces. These CCPs harbour nearly 30 disease-linked missense mutations. We have also deployed small-angle X-ray scattering (SAXS) to investigate FH18-20 flexibility in solution using FH18-20 and FH19-20 constructs. In the crystal lattice FH18-20 adopts a "J"-shape: A approximately 122-degree tilt between the structurally highly similar modules 18 and 19 precedes an extended, linear arrangement of modules 19 and 20 as observed in previously determined structures of these two modules alone. However, under solution conditions FH18-20 adopts multiple conformations mediated by flexibility between CCPs 18 and 19. We also pinpoint the locations of disease-associated missense mutations on the module 18 surface and discuss our data in the context of the C3b:FH interaction.
Structural Analysis of the C-Terminal Region (Modules 18-20) of Complement Regulator Factor H (FH).,Morgan HP, Mertens HD, Guariento M, Schmidt CQ, Soares DC, Svergun DI, Herbert AP, Barlow PN, Hannan JP PLoS One. 2012;7(2):e32187. Epub 2012 Feb 28. PMID:22389686[18]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ault BH, Schmidt BZ, Fowler NL, Kashtan CE, Ahmed AE, Vogt BA, Colten HR. Human factor H deficiency. Mutations in framework cysteine residues and block in H protein secretion and intracellular catabolism. J Biol Chem. 1997 Oct 3;272(40):25168-75. PMID:9312129
- ↑ Sanchez-Corral P, Bellavia D, Amico L, Brai M, Rodriguez de Cordoba S. Molecular basis for factor H and FHL-1 deficiency in an Italian family. Immunogenetics. 2000 Apr;51(4-5):366-9. PMID:10803850
- ↑ Perez-Caballero D, Gonzalez-Rubio C, Gallardo ME, Vera M, Lopez-Trascasa M, Rodriguez de Cordoba S, Sanchez-Corral P. Clustering of missense mutations in the C-terminal region of factor H in atypical hemolytic uremic syndrome. Am J Hum Genet. 2001 Feb;68(2):478-84. Epub 2001 Jan 17. PMID:11170895 doi:S0002-9297(07)64099-3
- ↑ Richards A, Buddles MR, Donne RL, Kaplan BS, Kirk E, Venning MC, Tielemans CL, Goodship JA, Goodship TH. Factor H mutations in hemolytic uremic syndrome cluster in exons 18-20, a domain important for host cell recognition. Am J Hum Genet. 2001 Feb;68(2):485-90. Epub 2001 Jan 17. PMID:11170896 doi:S0002-9297(07)64100-7
- ↑ Caprioli J, Bettinaglio P, Zipfel PF, Amadei B, Daina E, Gamba S, Skerka C, Marziliano N, Remuzzi G, Noris M. The molecular basis of familial hemolytic uremic syndrome: mutation analysis of factor H gene reveals a hot spot in short consensus repeat 20. J Am Soc Nephrol. 2001 Feb;12(2):297-307. PMID:11158219
- ↑ Remuzzi G, Ruggenenti P, Codazzi D, Noris M, Caprioli J, Locatelli G, Gridelli B. Combined kidney and liver transplantation for familial haemolytic uraemic syndrome. Lancet. 2002 May 11;359(9318):1671-2. PMID:12020532 doi:10.1016/S0140-6736(02)08560-4
- ↑ Dragon-Durey MA, Fremeaux-Bacchi V, Loirat C, Blouin J, Niaudet P, Deschenes G, Coppo P, Herman Fridman W, Weiss L. Heterozygous and homozygous factor h deficiencies associated with hemolytic uremic syndrome or membranoproliferative glomerulonephritis: report and genetic analysis of 16 cases. J Am Soc Nephrol. 2004 Mar;15(3):787-95. PMID:14978182
- ↑ Licht C, Heinen S, Jozsi M, Loschmann I, Saunders RE, Perkins SJ, Waldherr R, Skerka C, Kirschfink M, Hoppe B, Zipfel PF. Deletion of Lys224 in regulatory domain 4 of Factor H reveals a novel pathomechanism for dense deposit disease (MPGN II). Kidney Int. 2006 Jul;70(1):42-50. Epub 2006 Apr 12. PMID:16612335 doi:10.1038/sj.ki.5000269
- ↑ Dragon-Durey MA, Fremeaux-Bacchi V, Loirat C, Blouin J, Niaudet P, Deschenes G, Coppo P, Herman Fridman W, Weiss L. Heterozygous and homozygous factor h deficiencies associated with hemolytic uremic syndrome or membranoproliferative glomerulonephritis: report and genetic analysis of 16 cases. J Am Soc Nephrol. 2004 Mar;15(3):787-95. PMID:14978182
- ↑ Warwicker P, Goodship TH, Donne RL, Pirson Y, Nicholls A, Ward RM, Turnpenny P, Goodship JA. Genetic studies into inherited and sporadic hemolytic uremic syndrome. Kidney Int. 1998 Apr;53(4):836-44. PMID:9551389 doi:10.1111/j.1523-1755.1998.00824.x
- ↑ Ying L, Katz Y, Schlesinger M, Carmi R, Shalev H, Haider N, Beck G, Sheffield VC, Landau D. Complement factor H gene mutation associated with autosomal recessive atypical hemolytic uremic syndrome. Am J Hum Genet. 1999 Dec;65(6):1538-46. PMID:10577907 doi:S0002-9297(07)63573-3
- ↑ Buddles MR, Donne RL, Richards A, Goodship J, Goodship TH. Complement factor H gene mutation associated with autosomal recessive atypical hemolytic uremic syndrome. Am J Hum Genet. 2000 May;66(5):1721-2. PMID:10762557 doi:10.1086/302877
- ↑ Perkins SJ, Goodship TH. Molecular modelling of the C-terminal domains of factor H of human complement: a correlation between haemolytic uraemic syndrome and a predicted heparin binding site. J Mol Biol. 2002 Feb 15;316(2):217-24. PMID:11851332 doi:10.1006/jmbi.2001.5337
- ↑ Caprioli J, Castelletti F, Bucchioni S, Bettinaglio P, Bresin E, Pianetti G, Gamba S, Brioschi S, Daina E, Remuzzi G, Noris M. Complement factor H mutations and gene polymorphisms in haemolytic uraemic syndrome: the C-257T, the A2089G and the G2881T polymorphisms are strongly associated with the disease. Hum Mol Genet. 2003 Dec 15;12(24):3385-95. Epub 2003 Oct 28. PMID:14583443 doi:10.1093/hmg/ddg363
- ↑ Neumann HP, Salzmann M, Bohnert-Iwan B, Mannuelian T, Skerka C, Lenk D, Bender BU, Cybulla M, Riegler P, Konigsrainer A, Neyer U, Bock A, Widmer U, Male DA, Franke G, Zipfel PF. Haemolytic uraemic syndrome and mutations of the factor H gene: a registry-based study of German speaking countries. J Med Genet. 2003 Sep;40(9):676-81. PMID:12960213
- ↑ Maga TK, Nishimura CJ, Weaver AE, Frees KL, Smith RJ. Mutations in alternative pathway complement proteins in American patients with atypical hemolytic uremic syndrome. Hum Mutat. 2010 Jun;31(6):E1445-60. doi: 10.1002/humu.21256. PMID:20513133 doi:10.1002/humu.21256
- ↑ Raychaudhuri S, Iartchouk O, Chin K, Tan PL, Tai AK, Ripke S, Gowrisankar S, Vemuri S, Montgomery K, Yu Y, Reynolds R, Zack DJ, Campochiaro B, Campochiaro P, Katsanis N, Daly MJ, Seddon JM. A rare penetrant mutation in CFH confers high risk of age-related macular degeneration. Nat Genet. 2011 Oct 23;43(12):1232-6. doi: 10.1038/ng.976. PMID:22019782 doi:10.1038/ng.976
- ↑ Morgan HP, Mertens HD, Guariento M, Schmidt CQ, Soares DC, Svergun DI, Herbert AP, Barlow PN, Hannan JP. Structural Analysis of the C-Terminal Region (Modules 18-20) of Complement Regulator Factor H (FH). PLoS One. 2012;7(2):e32187. Epub 2012 Feb 28. PMID:22389686 doi:10.1371/journal.pone.0032187
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