This gene encodes a cytoplasmic protein which contains a regulation of G-protein signaling (RGS) domain and a dishevelled and axin (DIX) domain. The encoded protein interacts with adenomatosis polyposis coli, catenin (cadherin-associated protein) beta 1, glycogen synthase kinase 3 beta, protein phosphatase 2, and itself. This protein functions as a negative regulator of the wingless-type MMTV integration site family, member 1 (WNT) signaling pathway and can induce apoptosis. The crystal structure of a portion of this protein, alone and in a complex with other proteins, has been resolved. Mutations in this gene have been associated with hepatocellular carcinoma, hepatoblastomas, ovarian endometriod adenocarcinomas, and medulloblastomas. Two transcript variants encoding distinct isoforms have been identified for this gene.[2]
Structure
The full-length human protein comprises 862 amino acids with a (predicted) molecular mass of 96 kDa. The N-terminal RGS domain, a GSK3 kinase interacting peptide of Axin1 and homologs of the C-terminal DIX domains have been solved at atomic resolution. Large WNT-downregulating central regions have been characterized as intrinsically disordered by biophysical experiments and bioinformatic analysis.[3] Biophysical destabilization of the folded RGS domain induces formation of nanoaggregates that expose and locally concentrate intrinsically disordered regions, which in turn misregulate Wnt signalling. Many other large IDPs are affected by missense mutations, such as BRCA1, Adenomatous polyposis coli(APC), CREB-binding protein/(CBP) and might be affected in similar ways by missense mutations of their folded domains.[4]
↑Anvarian Z, Nojima H, van Kappel EC, Madl T, Spit M, Viertler M, Jordens I, Low TY, van Scherpenzeel RC, Kuper I, Richter K, Heck AJ, Boelens R, Vincent JP, Rüdiger SG, Maurice MM (2016). "Axin cancer mutants form nanoaggregates to rewire the Wnt signaling network". Nat Struct Mol Biol. 23: 324–32. doi:10.1038/nsmb.3191. PMID26974125.
↑ 5.05.15.2Nakamura T, Hamada F, Ishidate T, Anai K, Kawahara K, Toyoshima K, Akiyama T (June 1998). "Axin, an inhibitor of the Wnt signalling pathway, interacts with beta-catenin, GSK-3beta and APC and reduces the beta-catenin level". Genes Cells. 3 (6): 395–403. doi:10.1046/j.1365-2443.1998.00198.x. PMID9734785.
↑ 7.07.17.2Zhang Y, Qiu WJ, Chan SC, Han J, He X, Lin SC (May 2002). "Casein kinase I and casein kinase II differentially regulate axin function in Wnt and JNK pathways". J. Biol. Chem. 277 (20): 17706–12. doi:10.1074/jbc.M111982200. PMID11884395.
↑Mao J, Wang J, Liu B, Pan W, Farr GH, Flynn C, Yuan H, Takada S, Kimelman D, Li L, Wu D (April 2001). "Low-density lipoprotein receptor-related protein-5 binds to Axin and regulates the canonical Wnt signaling pathway". Mol. Cell. 7 (4): 801–9. doi:10.1016/S1097-2765(01)00224-6. PMID11336703.
↑Zhang Y, Neo SY, Han J, Lin SC (August 2000). "Dimerization choices control the ability of axin and dishevelled to activate c-Jun N-terminal kinase/stress-activated protein kinase". J. Biol. Chem. 275 (32): 25008–14. doi:10.1074/jbc.M002491200. PMID10829020.
↑Yamamoto H, Hinoi T, Michiue T, Fukui A, Usui H, Janssens V, Van Hoof C, Goris J, Asashima M, Kikuchi A (July 2001). "Inhibition of the Wnt signaling pathway by the PR61 subunit of protein phosphatase 2A". J. Biol. Chem. 276 (29): 26875–82. doi:10.1074/jbc.M100443200. PMID11297546.
Further reading
Segditsas S, Tomlinson I (2007). "Colorectal cancer and genetic alterations in the Wnt pathway". Oncogene. 25 (57): 7531–7. doi:10.1038/sj.onc.1210059. PMID17143297.
Flint J, Thomas K, Micklem G, Raynham H, Clark K, Doggett NA, King A, Higgs DR (1997). "The relationship between chromosome structure and function at a human telomeric region". Nat. Genet. 15 (3): 252–7. doi:10.1038/ng0397-252. PMID9054936.
Hart MJ, de los Santos R, Albert IN, Rubinfeld B, Polakis P (1998). "Downregulation of beta-catenin by human Axin and its association with the APC tumor suppressor, beta-catenin and GSK3 beta". Curr. Biol. 8 (10): 573–81. doi:10.1016/S0960-9822(98)70226-X. PMID9601641.
Nakamura T, Hamada F, Ishidate T, Anai K, Kawahara K, Toyoshima K, Akiyama T (1998). "Axin, an inhibitor of the Wnt signalling pathway, interacts with beta-catenin, GSK-3beta and APC and reduces the beta-catenin level". Genes Cells. 3 (6): 395–403. doi:10.1046/j.1365-2443.1998.00198.x. PMID9734785.
Hsu W, Zeng L, Costantini F (1999). "Identification of a domain of Axin that binds to the serine/threonine protein phosphatase 2A and a self-binding domain". J. Biol. Chem. 274 (6): 3439–45. doi:10.1074/jbc.274.6.3439. PMID9920888.
Kodama S, Ikeda S, Asahara T, Kishida M, Kikuchi A (1999). "Axin directly interacts with plakoglobin and regulates its stability". J. Biol. Chem. 274 (39): 27682–8. doi:10.1074/jbc.274.39.27682. PMID10488109.
Jho Eh, Lomvardas S, Costantini F (2000). "A GSK3beta phosphorylation site in axin modulates interaction with beta-catenin and Tcf-mediated gene expression". Biochem. Biophys. Res. Commun. 266 (1): 28–35. doi:10.1006/bbrc.1999.1760. PMID10581160.
Ikeda S, Kishida M, Matsuura Y, Usui H, Kikuchi A (2000). "GSK-3beta-dependent phosphorylation of adenomatous polyposis coli gene product can be modulated by beta-catenin and protein phosphatase 2A complexed with Axin". Oncogene. 19 (4): 537–45. doi:10.1038/sj.onc.1203359. PMID10698523.
Satoh S, Daigo Y, Furukawa Y, Kato T, Miwa N, Nishiwaki T, Kawasoe T, Ishiguro H, Fujita M, Tokino T, Sasaki Y, Imaoka S, Murata M, Shimano T, Yamaoka Y, Nakamura Y (2000). "AXIN1 mutations in hepatocellular carcinomas, and growth suppression in cancer cells by virus-mediated transfer of AXIN1". Nat. Genet. 24 (3): 245–50. doi:10.1038/73448. PMID10700176.
Zhang Y, Neo SY, Han J, Lin SC (2000). "Dimerization choices control the ability of axin and dishevelled to activate c-Jun N-terminal kinase/stress-activated protein kinase". J. Biol. Chem. 275 (32): 25008–14. doi:10.1074/jbc.M002491200. PMID10829020.
Daniels RJ, Peden JF, Lloyd C, Horsley SW, Clark K, Tufarelli C, Kearney L, Buckle VJ, Doggett NA, Flint J, Higgs DR (2001). "Sequence, structure and pathology of the fully annotated terminal 2 Mb of the short arm of human chromosome 16". Hum. Mol. Genet. 10 (4): 339–52. doi:10.1093/hmg/10.4.339. PMID11157797.
Yamamoto H, Hinoi T, Michiue T, Fukui A, Usui H, Janssens V, Van Hoof C, Goris J, Asashima M, Kikuchi A (2001). "Inhibition of the Wnt signaling pathway by the PR61 subunit of protein phosphatase 2A". J. Biol. Chem. 276 (29): 26875–82. doi:10.1074/jbc.M100443200. PMID11297546.
Mao J, Wang J, Liu B, Pan W, Farr GH, Flynn C, Yuan H, Takada S, Kimelman D, Li L, Wu D (2001). "Low-density lipoprotein receptor-related protein-5 binds to Axin and regulates the canonical Wnt signaling pathway". Mol. Cell. 7 (4): 801–9. doi:10.1016/S1097-2765(01)00224-6. PMID11336703.
Rubinfeld B, Tice DA, Polakis P (2001). "Axin-dependent phosphorylation of the adenomatous polyposis coli protein mediated by casein kinase 1epsilon". J. Biol. Chem. 276 (42): 39037–45. doi:10.1074/jbc.M105148200. PMID11487578.