Interaction between the enamel matrix proteins amelogenin and ameloblastin

Ravindranath, Hanumanth H.; Chen, Li-Sha; Zeichner‐David, Margarita; Ishima, Rieko; Ravindranath, Rajeswari M.H.

doi:10.1016/j.bbrc.2004.08.207

Cited by 51 publications

(52 citation statements)

References 29 publications

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“…The anti-V5 antibody was able to detect the recombinant protein as a specific band of about 58 kDa, which is larger than the predicted molecular size of the AMBN-V5-His fusion protein. This higher molecular weight on SDS-PAGE is due to the unconventional protein property of AMBN (16). Primary dental epithelium bound to full-length AMBN (AB1) in a dose-dependent manner, as previously reported.…”

Section: Ambn Binding To Dental Epithelial Cells Is Inhibited By Hepasupporting

confidence: 52%

“…Recently, AMBN has been reported to appear in three different molecular sizes (37,55, and 66 kDa) in both ameloblasts and enamel matrix during postnatal development (35). There may be various transcripts of Ambn that are developmentally expressed and interact with AMEL (16). Interestingly, 37-kDa AMBN containing three heparin binding domains is expressed in the early stage of ameloblast differentiation.…”

Section: Discussionmentioning

confidence: 99%

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Critical Role of Heparin Binding Domains of Ameloblastin for Dental Epithelium Cell Adhesion and Ameloblastoma Proliferation

Sonoda

Iwamoto

Nakamura

et al. 2009

Journal of Biological Chemistry

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AMBN (ameloblastin)is an enamel matrix protein that regulates cell adhesion, proliferation, and differentiation of ameloblasts. In AMBN-deficient mice, ameloblasts are detached from the enamel matrix, continue to proliferate, and form a multiple cell layer; often, odontogenic tumors develop in the maxilla with age. However, the mechanism of AMBN functions in these biological processes remains unclear. By using recombinant AMBN proteins, we found that AMBN had heparin binding domains at the C-terminal half and that these domains were critical for AMBN binding to dental epithelial cells. Overexpression of fulllength AMBN protein inhibited proliferation of human ameloblastoma AM-1 cells, but overexpression of heparin binding domain-deficient AMBN protein had no inhibitory effect. In full-length AMBN-overexpressing AM-1 cells, the expression of Msx2, which is involved in the dental epithelial progenitor phenotype, was decreased, whereas the expression of cell proliferation inhibitors p21 and p27 was increased. We also found that the expression of enamelin, a marker of differentiated ameloblasts, was induced, suggesting that AMBN promotes odontogenic tumor differentiation. Thus, our results suggest that AMBN promotes cell binding through the heparin binding sites and plays an important role in preventing odontogenic tumor development by suppressing cell proliferation and maintaining differentiation phenotype through Msx2, p21, and p27.The extracellular matrix provides structural support for cells and regulates cell proliferation, migration, differentiation, and apoptosis for tissue development and homeostasis (1). The extracellular matrix also plays a crucial role in pathological processes and diseases, such as wound healing, tumorigenesis, and cancer development (2, 3). AMBN (ameloblastin), also known as amelin and sheathlin, is a tooth-specific extracellular matrix and the most abundant non-amelogenin enamel matrix protein (4 -6). AMBN is expressed primarily by ameloblasts, which are differentiated from the oral ectoderm and form a polarized single cell layer underlying the enamel matrix. In a previous study, we created Ambn-null mice and demonstrated that AMBN is required for cell attachment and polarization and for maintaining the differentiation state of ameloblasts and is essential for enamel formation (3). Overexpression of Ambn in transgenic mice causes abnormal enamel crystallite formation and enamel rod morphology (7). These results suggest that enamel formation and rod morphology are influenced by temporal and spatial expressions of AMBN and imply that the AMBN gene locus may be involved in the etiology of a number of cases of undiagnosed hereditary amelogenesis imperfecta (8). Further, it was reported that recombinant AMBN enhances pulpal wound healing and reparative dentine formation following pulpotomy procedures, suggesting that it functions as a signal molecule in epithelial-mesenchymal interactions (9).We previously reported that about 20% of Ambn-null mice developed an odontogenic tumor of dental ep...

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Section: Ambn Binding To Dental Epithelial Cells Is Inhibited By Hepasupporting

confidence: 52%

Section: Discussionmentioning

confidence: 99%

Critical Role of Heparin Binding Domains of Ameloblastin for Dental Epithelium Cell Adhesion and Ameloblastoma Proliferation

Sonoda

Iwamoto

Nakamura

et al. 2009

Journal of Biological Chemistry

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“…The "unstructured" nature of the oligomers makes them ideal for interaction with various targets, such as apatite (52,53), enamelin (53,54), ameloblastin (55), and the cell surface (56). Fluorescence experiments with single tryptophan amelogenins revealed that whereas the C terminus of amelogenin (specifically residue Trp 161 ) resides in an aqueous environment even when assembled into oligomers or nanospheres the N-terminal region around Trp 25 and Trp 45 moves into a more hydrophobic environment as soon as monomers begin to assemble into oligomers.…”

Section: Discussionmentioning

confidence: 99%

Dissecting Amelogenin Protein Nanospheres

Bromley

Kiss

Lokappa

et al. 2011

Journal of Biological Chemistry

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Amelogenin self-assembles to form an extracellular protein matrix, which serves as a template for the continuously growing enamel apatite crystals. is involved in protein-protein interaction. The truncated rP148 formed similar but smaller oligomers, suggesting that the C terminus is not critical for amelogenin oligomerization. We propose a model for nanosphere formation via oligomers, and we predict that nanospheres will break up to form oligomers in mildly acidic environments via histidine protonation. We further suggest that oligomeric structures might be functional components during maturation of enamel apatite.

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“…Tooth enamel, the most mineralized tissue in the body, is formed by an evolutionarily highly conserved process that is controlled by extracellular matrix proteins [1]. During the secretory stage of enamel formation, the three major proteins secreted by ameloblasts are amelogenin (Am), ameloblastin and enamelin [2].…”

Section: Introductionmentioning

confidence: 99%

“…During the secretory stage of enamel formation, the three major proteins secreted by ameloblasts are amelogenin (Am), ameloblastin and enamelin [2]. Upon secretion from ameloblasts, the enamel matrix proteins assemble to facilitate crystal nucleation and growth in appropriate physico-chemical microenvironment [1]. The amelogenins constitute about 90% of the enamel matrix proteins and play an important role in enamel biomineralization [3].…”

Section: Introductionmentioning

confidence: 99%

Expression and Purification of Recombinant Human Amelogenin Using the Prokaryotic Expression System

Feng¹,

Yao²,

Du³

et al. 2016

Proceedings of the 2016 International Conference on Advanced Materials Science and Environmental Engineering

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Abstract-The amelogenins (Am) constitute about 90% of the enamel matrix proteins and play a critical role in enamel biomineralization. This study aimed to express and characterize recombinant human amelogenin (rAm) protein in the prokaryotic expression system in quantities sufficient for structural and functional research. Human cDNA coding for a 175 amino acid amelogenin protein was subcloned into the pET-28a(+) vector, this system adds a hexa-histidine tag to N-terminal amino acid of the expressed protein, enabling effective three steps purification by Ni

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Interaction between the enamel matrix proteins amelogenin and ameloblastin

Cited by 51 publications

References 29 publications

Critical Role of Heparin Binding Domains of Ameloblastin for Dental Epithelium Cell Adhesion and Ameloblastoma Proliferation

Critical Role of Heparin Binding Domains of Ameloblastin for Dental Epithelium Cell Adhesion and Ameloblastoma Proliferation

Dissecting Amelogenin Protein Nanospheres

Expression and Purification of Recombinant Human Amelogenin Using the Prokaryotic Expression System

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