Ameloblastin

AMBN
Identifiers
Aliases	AMBN , AI1F, Sheathlin, ameloblastin
External IDs	OMIM: 601259; MGI: 104655; HomoloGene: 7625; GeneCards: AMBN; OMA:AMBN - orthologs
Gene location (Human) Chr. Chromosome 4 (human) [1] Band 4q13.3 Start 70,592,256 bp [1] End 70,607,288 bp [1]
Gene location (Mouse) Chr. Chromosome 5 (mouse) [2] Band 5 E1|5 43.63 cM Start 88,603,850 bp [2] End 88,616,390 bp [2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in testicle putamen caudate nucleus gonad nucleus accumbens islet of Langerhans Epithelium of choroid plexus ventricular zone prefrontal cortex mesencephalon Top expressed in molar membranous bone maxilla sexually immature organism mandible inner enamel epithelium fossa lumbar subsegment of spinal cord incisor dermis More reference expression data BioGPS n/a
Gene ontology Molecular function structural constituent of tooth enamel growth factor activity protein binding Cellular component extracellular region endoplasmic reticulum lumen Biological process odontogenesis of dentin-containing tooth biomineral tissue development cell adhesion cell population proliferation post-translational protein modification regulation of signaling receptor activity regulation of cell population proliferation signal transduction Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 258 11698 Ensembl ENSG00000178522 ENSMUSG00000029288 UniProt Q9NP70 O55189 RefSeq (mRNA) NM_016519 NM_009664 NM_001303431 RefSeq (protein) NP_057603 NP_001290360 NP_033794 Location (UCSC) Chr 4: 70.59 – 70.61 Mb Chr 5: 88.6 – 88.62 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Ameloblastin (abbreviated AMBN and also known as sheathlin or amelin) is an enamel matrix protein that in humans is encoded by the AMBN gene. ^[5]

Function

Ameloblastin is a specific protein found in tooth enamel. Although less than 5% of enamel consists of protein, ameloblastins constitute 5–10% of all enamel protein, making it the second most abundant enamel matrix protein. ^[6] This protein is formed by ameloblasts during the early secretory to late maturation stages of amelogenesis. Although not completely understood, the function of ameloblastins is believed to be in controlling the elongation of enamel crystals and generally directing enamel mineralization during tooth development. Ameloblastin helps in the growth of a crystalline enameloid layer consisting of randomly oriented short enamel crystals. ^[7] Ameloblastin cleavage products are found in the sheath space between rod and interrod enamel, while intact ameloblastin accumulates on the enamel rods. This difference in localization is thought to maintain the boundary between rod and interrod enamel. ^{[6] [8]}

Ameloblastin is generally implicated in enamel development, but may also have a role in root development. ^[6] Other possible actions include bone remodeling and repair, although this function has yet to be definitively proven. ^[6]

Other significant proteins in enamel are amelogenins, enamelins, and tuftelins.

Clinical significance

Mutations in AMBN cause amelogenesis imperfecta, a disease characterized by abnormal enamel formation resulting in discolored, pitted, or spotted enamel. ^[9] These mutations are rare, and follow an autosomal recessive pattern of inheritance. ^[6]

References

1. GRCh38: Ensembl release 89: ENSG00000178522 – Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000029288 – Ensembl, May 2017
3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
5. "Entrez Gene: Ameloblastin (enamel matrix protein)".
6. Hu JC, Chun YH, Al Hazzazzi T, Simmer JP (2007). "Enamel formation and amelogenesis imperfecta". Cells Tissues Organs. 186 (1): 78–85. doi:10.1159/000102683. PMID   17627121. S2CID   28367304.
7. Pandya M, Diekwisch TG (December 2021). "Amelogenesis: Transformation of a protein-mineral matrix into tooth enamel". Journal of Structural Biology. 213 (4) 107809. doi:10.1016/j.jsb.2021.107809. PMC   8665087 . PMID   34748943.
8. Bartlett JD (September 2013). "Dental enamel development: proteinases and their enamel matrix substrates". ISRN Dentistry. 2013 684607. doi: 10.1155/2013/684607 . PMC   3789414 . PMID   24159389.
9. Poulter JA, Murillo G, Brookes SJ, Smith CE, Parry DA, Silva S, et al. (October 2014). "Deletion of ameloblastin exon 6 is associated with amelogenesis imperfecta". Human Molecular Genetics. 23 (20): 5317–5324. doi:10.1093/hmg/ddu247. PMC   4168819 . PMID   24858907.

• This article incorporates text from the United States National Library of Medicine, which is in the public domain.

Further reading

• Bartlett JD, Simmer JP (1999). "Proteinases in developing dental enamel". Critical Reviews in Oral Biology and Medicine. 10 (4): 425–441. doi: 10.1177/10454411990100040101 . PMID   10634581.
• MacDougall M, DuPont BR, Simmons D, Reus B, Krebsbach P, Kärrman C, et al. (April 1997). "Ameloblastin gene (AMBN) maps within the critical region for autosomal dominant amelogenesis imperfecta at chromosome 4q21". Genomics. 41 (1): 115–118. doi:10.1006/geno.1997.4643. PMID   9126491.
• Kuroda S, Wazen R, Sellin K, Tanaka E, Moffatt P, Nanci A (July 2011). "Ameloblastin is not implicated in bone remodelling and repair". European Cells & Materials. 22: 56–66, discussion 66–7. doi: 10.22203/eCM.v022a05 . PMID   21761392.
• Perdigão PF, Carvalho VM, DE Marco L, Gomez RS (August 2009). "Mutation of ameloblastin gene in calcifying epithelial odontogenic tumor". Anticancer Research. 29 (8): 3065–3067. PMID   19661317.
• Tamburstuen MV, Reseland JE, Spahr A, Brookes SJ, Kvalheim G, Slaby I, et al. (February 2011). "Ameloblastin expression and putative autoregulation in mesenchymal cells suggest a role in early bone formation and repair". Bone. 48 (2): 406–413. doi:10.1016/j.bone.2010.09.007. PMC   4469498 . PMID   20854943.
• Toyosawa S, Fujiwara T, Ooshima T, Shintani S, Sato A, Ogawa Y, et al. (October 2000). "Cloning and characterization of the human ameloblastin gene". Gene. 256 (1–2): 1–11. doi:10.1016/s0378-1119(00)00379-6. PMID   11054529.
• Patir A, Seymen F, Yildirim M, Deeley K, Cooper ME, Marazita ML, Vieira AR (2008). "Enamel formation genes are associated with high caries experience in Turkish children". Caries Research. 42 (5): 394–400. doi:10.1159/000154785. PMC   2820320 . PMID   18781068.
• Lee SK, Krebsbach PH, Matsuki Y, Nanci A, Yamada KM, Yamada Y (December 1996). "Ameloblastin expression in rat incisors and human tooth germs". The International Journal of Developmental Biology. 40 (6): 1141–1150. PMID   9032019.
• Niu CH, Li TJ (November 2006). "[Mutation and polymorphism of the ameloblastin gene in ameloblastomas]". Zhonghua Kou Qiang Yi Xue Za Zhi = Zhonghua Kouqiang Yixue Zazhi = Chinese Journal of Stomatology (in Chinese). 41 (11): 678–681. PMID   17331365.

External links

• Human AMBN genome location and AMBN gene details page in the UCSC Genome Browser .