The Amelogenin C-Terminus Is Required for Enamel Development

• Published in: Journal of dental research Vol. 89; no. 2; pp. 165 - 169
• Main Authors: Pugach, M.K., Li, Y., Suggs, C., Wright, J.T., Aragon, M.A., Yuan, Z.A., Simmons, D., Kulkarni, A.B., Gibson, C.W.
• Format: Journal Article
• Language: English
• Published: Washington, DC SAGE Publications 01.02.2010; International Association for Dental Research; SAGE PUBLICATIONS, INC
• Subjects: Amelogenin - chemistry; Amelogenin - physiology; Amino Acids - physiology; Animals; Biological and medical sciences; Dental Enamel - abnormalities; Dental Enamel - chemistry; Dental Enamel - growth & development; Dental Enamel Hypoplasia - genetics; Facial bones, jaws, teeth, parodontium: diseases, semeiology; Female; Fundamental and applied biological sciences. Psychology; Male; Medical sciences; Mice; Mice, Knockout; Mice, Transgenic; Mouth. Exocrine and endocrine salivary glands. Teeth. Esophagus; Mutagenesis, Site-Directed; Non tumoral diseases; Otorhinolaryngology. Stomatology; Research Reports; Sequence Deletion; Vertebrates: digestive system; X-Ray Microtomography; transgenic mice; enamel; amelogenin; X ray microtomography; Amelogenesis; Stomatology; Dental disease; Rodentia; Transgenic animal; Genetic disease; Odontogenesis; Tooth enamel; Vertebrata; Mammalia; Mouse; Aminoacid; Tooth; Amelogenesis imperfecta; Amelogenin; Dental dysplasia
• ISSN: 0022-0345; 1544-0591
• DOI: 10.1177/0022034509358392

The abundant amelogenin proteins are responsible for generating proper enamel thickness and structure, and most amelogenins include a conserved hydrophilic C-terminus. To evaluate the importance of the C-terminus, we generated transgenic mice that express an amelogenin lacking the C-terminal 13 amino acids (CTRNC). MicroCT analysis of TgCTRNC29 teeth (low transgene number) indicated that molar enamel density was similar to that of wild-type mice, but TgCTRNC18 molar enamel (high transgene number) was deficient, indicating that extra transgene copies were associated with a more severe phenotype. When amelogenin-null (KO) and TgCTRNC transgenic mice were mated, density and volume of molar enamel from TgCTRNCKO offspring were not different from those of KO mice, indicating that neither TgCTRNC18 nor TgCTRNC29 rescued enamel’s physical characteristics. Because transgenic full-length amelogenin partially rescues both density and volume of KO molar enamel, it was concluded that the amelogenin C-terminus is essential for proper enamel density, volume, and organization.