| Structural highlights
Disease
LRP6_HUMAN Coronary artery disease - hyperlipidemia - hypertension - diabetes - osteoporosis. The disease is caused by mutations affecting the gene represented in this entry.
Function
LRP6_HUMAN Component of the Wnt-Fzd-LRP5-LRP6 complex that triggers beta-catenin signaling through inducing aggregation of receptor-ligand complexes into ribosome-sized signalsomes. Cell-surface coreceptor of Wnt/beta-catenin signaling, which plays a pivotal role in bone formation. The Wnt-induced Fzd/LRP6 coreceptor complex recruits DVL1 polymers to the plasma membrane which, in turn, recruits the AXIN1/GSK3B-complex to the cell surface promoting the formation of signalsomes and inhibiting AXIN1/GSK3-mediated phosphorylation and destruction of beta-catenin. Required for posterior patterning of the epiblast during gastrulation (By similarity).[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
Publication Abstract from PubMed
Kremen 1 and 2 have been identified as co-receptors for Dickkopf (Dkk) proteins, hallmark secreted antagonists of canonical Wnt signaling. We present here three crystal structures of the ectodomain of human Kremen1 (KRM1ECD) at resolutions between 1.9 and 3.2 A. KRM1ECD emerges as a rigid molecule with tight interactions stabilizing a triangular arrangement of its Kringle, WSC, and CUB structural domains. The structures reveal an unpredicted homology of the WSC domain to hepatocyte growth factor. We further report the general architecture of the ternary complex formed by the Wnt co-receptor Lrp5/6, Dkk, and Krm, determined from a low-resolution complex crystal structure between beta-propeller/EGF repeats (PE) 3 and 4 of the Wnt co-receptor LRP6 (LRP6PE3PE4), the cysteine-rich domain 2 (CRD2) of DKK1, and KRM1ECD. DKK1CRD2 is sandwiched between LRP6PE3 and KRM1Kringle-WSC. Modeling studies supported by surface plasmon resonance suggest a direct interaction site between Krm1CUB and Lrp6PE2.
Structure of the Dual-Mode Wnt Regulator Kremen1 and Insight into Ternary Complex Formation with LRP6 and Dickkopf.,Zebisch M, Jackson VA, Zhao Y, Jones EY Structure. 2016 Sep 6;24(9):1599-1605. doi: 10.1016/j.str.2016.06.020. Epub 2016 , Aug 11. PMID:27524201[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Semenov MV, Tamai K, Brott BK, Kuhl M, Sokol S, He X. Head inducer Dickkopf-1 is a ligand for Wnt coreceptor LRP6. Curr Biol. 2001 Jun 26;11(12):951-61. PMID:11448771
- ↑ Mao B, Wu W, Li Y, Hoppe D, Stannek P, Glinka A, Niehrs C. LDL-receptor-related protein 6 is a receptor for Dickkopf proteins. Nature. 2001 May 17;411(6835):321-5. PMID:11357136 doi:10.1038/35077108
- ↑ Li X, Zhang Y, Kang H, Liu W, Liu P, Zhang J, Harris SE, Wu D. Sclerostin binds to LRP5/6 and antagonizes canonical Wnt signaling. J Biol Chem. 2005 May 20;280(20):19883-7. Epub 2005 Mar 18. PMID:15778503 doi:10.1074/jbc.M413274200
- ↑ Zeng X, Tamai K, Doble B, Li S, Huang H, Habas R, Okamura H, Woodgett J, He X. A dual-kinase mechanism for Wnt co-receptor phosphorylation and activation. Nature. 2005 Dec 8;438(7069):873-7. PMID:16341017 doi:10.1038/nature04185
- ↑ Swiatek W, Kang H, Garcia BA, Shabanowitz J, Coombs GS, Hunt DF, Virshup DM. Negative regulation of LRP6 function by casein kinase I epsilon phosphorylation. J Biol Chem. 2006 May 5;281(18):12233-41. Epub 2006 Mar 2. PMID:16513652 doi:10.1074/jbc.M510580200
- ↑ Wei Q, Yokota C, Semenov MV, Doble B, Woodgett J, He X. R-spondin1 is a high affinity ligand for LRP6 and induces LRP6 phosphorylation and beta-catenin signaling. J Biol Chem. 2007 May 25;282(21):15903-11. Epub 2007 Mar 30. PMID:17400545 doi:10.1074/jbc.M701927200
- ↑ Mi K, Johnson GV. Regulated proteolytic processing of LRP6 results in release of its intracellular domain. J Neurochem. 2007 Apr;101(2):517-29. Epub 2007 Feb 26. PMID:17326769 doi:10.1111/j.1471-4159.2007.04447.x
- ↑ Piao S, Lee SH, Kim H, Yum S, Stamos JL, Xu Y, Lee SJ, Lee J, Oh S, Han JK, Park BJ, Weis WI, Ha NC. Direct inhibition of GSK3beta by the phosphorylated cytoplasmic domain of LRP6 in Wnt/beta-catenin signaling. PLoS One. 2008;3(12):e4046. doi: 10.1371/journal.pone.0004046. Epub 2008 Dec 24. PMID:19107203 doi:10.1371/journal.pone.0004046
- ↑ Chen M, Philipp M, Wang J, Premont RT, Garrison TR, Caron MG, Lefkowitz RJ, Chen W. G Protein-coupled receptor kinases phosphorylate LRP6 in the Wnt pathway. J Biol Chem. 2009 Dec 11;284(50):35040-8. doi: 10.1074/jbc.M109.047456. Epub 2009, Oct 2. PMID:19801552 doi:10.1074/jbc.M109.047456
- ↑ Wu G, Huang H, Garcia Abreu J, He X. Inhibition of GSK3 phosphorylation of beta-catenin via phosphorylated PPPSPXS motifs of Wnt coreceptor LRP6. PLoS One. 2009;4(3):e4926. doi: 10.1371/journal.pone.0004926. Epub 2009 Mar 18. PMID:19293931 doi:10.1371/journal.pone.0004926
- ↑ Zebisch M, Jackson VA, Zhao Y, Jones EY. Structure of the Dual-Mode Wnt Regulator Kremen1 and Insight into Ternary Complex Formation with LRP6 and Dickkopf. Structure. 2016 Sep 6;24(9):1599-1605. doi: 10.1016/j.str.2016.06.020. Epub 2016 , Aug 11. PMID:27524201 doi:http://dx.doi.org/10.1016/j.str.2016.06.020
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