Structural highlightsDiseaseACVL1_HUMAN Defects in ACVRL1 are the cause of hereditary hemorrhagic telangiectasia type 2 (HHT2) [MIM:600376; also known as Osler-Rendu-Weber syndrome 2 (ORW2). HHT2 is an autosomal dominant multisystemic vascular dysplasia, characterized by recurrent epistaxis, muco-cutaneous telangiectases, gastro-intestinal hemorrhage, and pulmonary, cerebral and hepatic arteriovenous malformations; all secondary manifestations of the underlying vascular dysplasia.[1] [2] [3] [4] [5] [6] [7] [8] [9]
FunctionACVL1_HUMAN Type I receptor for TGF-beta family ligands BMP9/GDF2 and BMP10 and important regulator of normal blood vessel development. On ligand binding, forms a receptor complex consisting of two type II and two type I transmembrane serine/threonine kinases. Type II receptors phosphorylate and activate type I receptors which autophosphorylate, then bind and activate SMAD transcriptional regulators. May bind activin as well.[10] [11]
Publication Abstract from PubMed
Bone morphogenetic proteins (BMPs) are secreted signaling proteins - they transduce their signals by assembling complexes comprised of one of three known type II receptors and one of four known type I receptors. BMP-9 binds and signals through the type I receptor Alk1, but not other Alks, while BMP-2, -4, and -7 bind and signal through Alk3, and the close homologue Alk6, but not Alk1. The present results, which include the determination of the Alk1 structure using NMR and identification of residues important for binding using SPR, show that the beta-strand framework of Alk1 is highly similar to Alk3, yet there are significant differences in loops shown previously to be important for binding. The most pronounced difference is in the N-terminal portion of the beta4-beta5 loop, which is structurally ordered and includes a similarly placed but shorter helix in Alk1 compared to Alk3. The altered conformation of the beta4-beta5 loop, and to lesser extent beta1-beta2 loop, cause clashes when Alk1 is positioned onto BMP-9 in the manner that Alk3 is positioned onto BMP-2. This necessitates an alternative manner of binding, which is supported by a model of the BMP-9/Alk1 complex constructed using the program RosettaDock. The model shows that Alk1 is positioned similar to Alk3 but is rotated by 40 deg. The alternate positioning allows Alk1 to bind BMP-9 through a large hydrophobic interface, consistent with mutational analysis that identified several residues in the central portion of the beta4-beta5 loop that contribute significantly to binding and are nonconservatively substituted relative to the corresponding residues in Alk3.
Structure of the Alk1 extracellular domain and characterization of its bone morphogenetic protein (BMP) binding properties.,Mahlawat P, Ilangovan U, Biswas T, Sun LZ, Hinck AP Biochemistry. 2012 Aug 14;51(32):6328-41. Epub 2012 Aug 2. PMID:22799562[12]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
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- ↑ Johnson DW, Berg JN, Baldwin MA, Gallione CJ, Marondel I, Yoon SJ, Stenzel TT, Speer M, Pericak-Vance MA, Diamond A, Guttmacher AE, Jackson CE, Attisano L, Kucherlapati R, Porteous ME, Marchuk DA. Mutations in the activin receptor-like kinase 1 gene in hereditary haemorrhagic telangiectasia type 2. Nat Genet. 1996 Jun;13(2):189-95. PMID:8640225 doi:10.1038/ng0696-189
- ↑ Klaus DJ, Gallione CJ, Anthony K, Yeh EY, Yu J, Lux A, Johnson DW, Marchuk DA. Novel missense and frameshift mutations in the activin receptor-like kinase-1 gene in hereditary hemorrhagic telangiectasia. Mutations in brief no. 164. Online. Hum Mutat. 1998;12(2):137. PMID:10694922 doi:<137::AID-HUMU16>3.0.CO;2-J 10.1002/(SICI)1098-1004(1998)12:2<137::AID-HUMU16>3.0.CO;2-J
- ↑ Abdalla SA, Pece-Barbara N, Vera S, Tapia E, Paez E, Bernabeu C, Letarte M. Analysis of ALK-1 and endoglin in newborns from families with hereditary hemorrhagic telangiectasia type 2. Hum Mol Genet. 2000 May 1;9(8):1227-37. PMID:10767348
- ↑ Kjeldsen AD, Brusgaard K, Poulsen L, Kruse T, Rasmussen K, Green A, Vase P. Mutations in the ALK-1 gene and the phenotype of hereditary hemorrhagic telangiectasia in two large Danish families. Am J Med Genet. 2001 Feb 1;98(4):298-302. PMID:11170071
- ↑ Trembath RC, Thomson JR, Machado RD, Morgan NV, Atkinson C, Winship I, Simonneau G, Galie N, Loyd JE, Humbert M, Nichols WC, Morrell NW, Berg J, Manes A, McGaughran J, Pauciulo M, Wheeler L. Clinical and molecular genetic features of pulmonary hypertension in patients with hereditary hemorrhagic telangiectasia. N Engl J Med. 2001 Aug 2;345(5):325-34. PMID:11484689 doi:10.1056/NEJM200108023450503
- ↑ Harrison RE, Flanagan JA, Sankelo M, Abdalla SA, Rowell J, Machado RD, Elliott CG, Robbins IM, Olschewski H, McLaughlin V, Gruenig E, Kermeen F, Halme M, Raisanen-Sokolowski A, Laitinen T, Morrell NW, Trembath RC. Molecular and functional analysis identifies ALK-1 as the predominant cause of pulmonary hypertension related to hereditary haemorrhagic telangiectasia. J Med Genet. 2003 Dec;40(12):865-71. PMID:14684682
- ↑ Lesca G, Plauchu H, Coulet F, Lefebvre S, Plessis G, Odent S, Riviere S, Leheup B, Goizet C, Carette MF, Cordier JF, Pinson S, Soubrier F, Calender A, Giraud S. Molecular screening of ALK1/ACVRL1 and ENG genes in hereditary hemorrhagic telangiectasia in France. Hum Mutat. 2004 Apr;23(4):289-99. PMID:15024723 doi:10.1002/humu.20017
- ↑ Kuehl HK, Caselitz M, Hasenkamp S, Wagner S, El-Harith el-HA, Manns MP, Stuhrmann M. Hepatic manifestation is associated with ALK1 in hereditary hemorrhagic telangiectasia: identification of five novel ALK1 and one novel ENG mutations. Hum Mutat. 2005 Mar;25(3):320. PMID:15712270 doi:10.1002/humu.9311
- ↑ Mahlawat P, Ilangovan U, Biswas T, Sun LZ, Hinck AP. Structure of the Alk1 extracellular domain and characterization of its bone morphogenetic protein (BMP) binding properties. Biochemistry. 2012 Aug 14;51(32):6328-41. Epub 2012 Aug 2. PMID:22799562 doi:10.1021/bi300942x
- ↑ Townson SA, Martinez-Hackert E, Greppi C, Lowden P, Sako D, Liu J, Ucran JA, Liharska K, Underwood KW, Seehra J, Kumar R, Grinberg AV. Specificity and structure of a high affinity activin receptor-like kinase 1 (ALK1) signaling complex. J Biol Chem. 2012 Jun 20. PMID:22718755 doi:10.1074/jbc.M112.377960
- ↑ Mahlawat P, Ilangovan U, Biswas T, Sun LZ, Hinck AP. Structure of the Alk1 extracellular domain and characterization of its bone morphogenetic protein (BMP) binding properties. Biochemistry. 2012 Aug 14;51(32):6328-41. Epub 2012 Aug 2. PMID:22799562 doi:10.1021/bi300942x
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