Enamel matrix serine proteinase 1 (EMSP1) is proposed to process enamel proteins during the secretory stage, and degrade enamel proteins during the early maturation stage of amelogenesis. EMSP1 is believed to be critical for proper dental enamel formation and defects in the human EMSP1 gene are suspected of causing amelogenesis imperfecta. Two hypotheses are tested: l. EMSP1 function is essential for the correct processing of enamel matrix proteins during the secretory stage of enamel formation, and that a loss of function can result in hypoplastic enamel. 2. EMSP1 function is essential for the degradation of enamel matrix proteins during the transition/early maturation stages of enamel formation, and that a loss of function can result in hypommeralized enamel. The following 4 Specific.
Aims are proposed to test these hypotheses: l. To determine the temporal and spatial expression of EMSP1 during the secretory. transition. and maturation stages of enamel biomineralization. In situ hybridization and immunohistochemistry will be performed on mouse maxillae and mandibles. The first and second molars and incisors will be analyzed from newborn, postnatal (PN) days 2, 4, 6, 8 and 14 and adult. 2. To characterize the enzymatic activity of EMSP1 on amelogenin. Recombinant pig amelogenin will be digested by recombinant pig EMSP1 in vitro. The digestion products will be characterized by Edman degradation and mass spectrometry and compared to amelogenin cleavage sites that occur in vivo. 3. To characterize enamel formation in the absence of mouse EMSP1 expression. EMSP1 knock-out mice will be generated and characterized. 4. To determine the genetic linkage of the human EMSP1 gene with inherited defects of dental enamel formation. In collaboration with 3 laboratories that have assembled large numbers of kindreds suffering for amelogenesis imperfecta (AI), a candidate gene approach will be used to establish linkage between the human EMSP1 gene and AI . Accomplishing these aims will gain important insights into the action of EMSP1 in the organization, processing, turnover, and degradation of enamel matrix proteins during enamel biomineralization.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
7R01DE012769-04
Application #
6697001
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Program Officer
Kousvelari, Eleni
Project Start
2002-09-01
Project End
2005-02-28
Budget Start
2002-09-01
Budget End
2003-02-28
Support Year
4
Fiscal Year
2002
Total Cost
$197,527
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Biology
Type
Schools of Dentistry
DUNS #
791277940
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Hu, Yuanyuan; Smith, Charles E; Richardson, Amelia S et al. (2016) MMP20, KLK4, and MMP20/KLK4 double null mice define roles for matrix proteases during dental enamel formation. Mol Genet Genomic Med 4:178-96
Smith, Charles E; Hu, Yuanyuan; Hu, Jan C-C et al. (2016) Ultrastructure of early amelogenesis in wild-type, Amelx-/-, and Enam-/- mice: enamel ribbon initiation on dentin mineral and ribbon orientation by ameloblasts. Mol Genet Genomic Med 4:662-683
Lee, S-K; Seymen, F; Kang, H-Y et al. (2010) MMP20 hemopexin domain mutation in amelogenesis imperfecta. J Dent Res 89:46-50
Kim, J-W; Simmer, J P (2007) Hereditary dentin defects. J Dent Res 86:392-9
Iwata, Takanori; Yamakoshi, Yasuo; Simmer, James P et al. (2007) Establishment of porcine pulp-derived cell lines and expression of recombinant dentin sialoprotein and recombinant dentin matrix protein-1. Eur J Oral Sci 115:48-56
Hu, Jan C-C; Simmer, James P (2007) Developmental biology and genetics of dental malformations. Orthod Craniofac Res 10:45-52
Kobayashi, K; Yamakoshi, Y; Hu, J C-C et al. (2007) Splicing determines the glycosylation state of ameloblastin. J Dent Res 86:962-7
Hu, Jan C-C; Chun, Yong-Hee P; Al Hazzazzi, Turki et al. (2007) Enamel formation and amelogenesis imperfecta. Cells Tissues Organs 186:78-85
Iwata, T; Yamakoshi, Y; Hu, J C-C et al. (2007) Processing of ameloblastin by MMP-20. J Dent Res 86:153-7
Chun, Yong-Hee P; Yamakoshi, Yasuo; Kim, Jung-Wook et al. (2006) Porcine SPARC: isolation from dentin, cDNA sequence, and computer model. Eur J Oral Sci 114 Suppl 1:78-85; discussion 93-5, 379-80

Showing the most recent 10 out of 28 publications