This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Iwata, T. Articles by Simmer, J.P. Search for Related Content PubMed PubMed Citation Articles by Iwata, T. Articles by Simmer, J.P. Pubmed/NCBI databases Genetics Home Reference Social Bookmarking                         What's this?

Processing of Ameloblastin by MMP-20

¹ Department of Biologic and Materials Sciences and
² Department of Orthodontics and Pediatric Dentistry, Dental Research Lab, University of Michigan School of Dentistry, 1210 Eisenhower Place, Ann Arbor, MI 48108, USA;
³ Department of Hard Tissue Engineering, Tokyo Medical and Dental University, Tokyo, Japan; and
⁴ Department of Cytokine Biology, The Forsyth Institute Boston, MA, USA

Correspondence: ^* corresponding author, jsimmer{at}umich.edu

Ameloblastin (AMBN) cleavage products are the most abundant non-amelogenin proteins in the enamel matrix of developing teeth. AMBN N-terminal cleavage products accumulate in the sheath space between enamel rods, while AMBN C-terminal products localize within rods. We tested the hypothesis that MMP-20 is the protease that cleaves AMBN. Glycosylated recombinant porcine AMBN (rpAMBN) was expressed in human kidney 293F cells, and recombinant porcine enamelysin (rpMMP-20) was expressed in bacteria. The purified proteins were incubated together at an enzyme:substrate ratio of 1:100. N-terminal sequencing of AMBN digestion products determined that rpMMP-20 cleaved rpAMBN after Pro², Gln¹³⁰, Gln¹³⁹, Arg¹⁷⁰, and Ala²²². This shows that MMP-20 generates the 23-kDa AMBN starting at Tyr²²³, as well as the 17-kDa (Val¹-Arg¹⁷⁰) and 15-kDa (Val¹-Gln¹³⁰) AMBN cleavage products that concentrate in the sheath space during the secretory stage. We conclude that MMP-20 processes ameloblastin in vitro and in vivo.

Key Words: enamelysin • ameloblastin • AMBN • MMP-20 • enamel • amelogenesis

Journal of Dental Research, Vol. 86, No. 2, 153-157 (2007)
DOI: 10.1177/154405910708600209


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				A. Sonoda, T. Iwamoto, T. Nakamura, E. Fukumoto, K. Yoshizaki, A. Yamada, M. Arakaki, H. Harada, K. Nonaka, S. Nakamura, et al. Critical Role of Heparin Binding Domains of Ameloblastin for Dental Epithelium Cell Adhesion and Ameloblastoma Proliferation J. Biol. Chem., October 2, 2009; 284(40): 27176 - 27184. [Abstract] [Full Text] [PDF]

				J. C.-C. Hu, Y. Hu, C. E. Smith, M. D. McKee, J. T. Wright, Y. Yamakoshi, P. Papagerakis, G. K. Hunter, J. Q. Feng, F. Yamakoshi, et al. Enamel Defects and Ameloblast-specific Expression in Enam Knock-out/lacZ Knock-in Mice J. Biol. Chem., April 18, 2008; 283(16): 10858 - 10871. [Abstract] [Full Text] [PDF]