John D. Bartlett

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Enamelysin is a tooth-specific matrix metalloproteinase that is expressed during the early through middle stages of enamel development. The enamel matrix proteins amelogenin, ameloblastin, and enamelin are also expressed during this same approximate developmental time period, suggesting that enamelysin may play a role in their hydrolysis. In support of this(More)
A cDNA encoding a new human matrix metalloproteinase (MMP) has been cloned from RNA prepared from odontoblastic cells. The open reading frame of the cloned cDNA codes for a polypeptide of 483 amino acids and is extensively similar to the sequence of recently described porcine enamelysin, suggesting that the isolated cDNA codes for the human homologue of(More)
For almost three decades, proteinases have been known to reside within developing dental enamel. However, identification and characterization of these proteinases have been slow and difficult, because they are present in very small quantities and they are difficult to purify directly from the mineralizing enamel. Enamel matrix proteins such as amelogenin,(More)
Two proteases are secreted into the enamel matrix of developing teeth. The early protease is enamelysin (MMP-20). The late protease is kallikrein 4 (KLK4). Mutations in MMP20 and KLK4 both cause autosomal recessive amelogenesis imperfecta, a condition featuring soft, porous enamel containing residual protein. MMP-20 is secreted along with enamel proteins by(More)
D uring mammalian tooth formation, two proteinases are secreted by ameloblasts: enamelysin (MMP-20) and kallikrein-4 (KLK4). Enamelysin is the early protease. It is expressed by ameloblasts throughout the secretory stage and part of the maturation stage. KLK4 is the late protease; its expression by ameloblasts begins in the transition stage and continues(More)
The maturation of dental enamel succeeds the degradation of organic matrix. Inhibition studies have shown that this degradation is accomplished by a serine-type proteinase. To isolate and characterize cDNA clones encoding this proteinase, we used two degenerate primer approaches to amplify part of the coding region using polymerase chain-reaction (PCR).(More)
The mechanism of how fluoride causes fluorosis remains unknown. Exposure to fluoride can inhibit protein synthesis, and this may also occur by agents that cause endoplasmic reticulum (ER) stress. When translated proteins fail to fold properly or become misfolded, ER stress response genes are induced that together comprise the unfolded protein response.(More)
Non-syndromic amelogenesis imperfecta (AI) is a collection of isolated inherited enamel malformations that follow X-linked, autosomal-dominant, or autosomal-recessive patterns of inheritance. The AI phenotype is also found in syndromes. We hypothesized that whole-exome sequencing of AI probands showing simplex or recessive patterns of inheritance would(More)
Matrix metalloproteinases (MMPs) have been detected in forming dental enamel and are thought to play an important role during enamel biomineralization. Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a membrane bound member of the MMP gene family that has previously been shown to be expressed by cells associated with bone and cartilage formation(More)
MT1-MMP is a cell-membrane-bound metalloenzyme that activates other proMMPs such as proMMP-2 and -13. We studied MT1-MMP expression in mature human odontoblasts and pulp tissue, the regulation of MT1-MMP expression by growth factors TGF-beta1 and BMP-2, and the activation of odontoblast-derived MMP-20 by MT1-MMP. MT1-MMP mRNA is expressed by native and(More)