Affinage

MMP20

Matrix metalloproteinase-20 · UniProt O60882

Length
483 aa
Mass
54.4 kDa
Annotated
2026-06-10
64 papers in source corpus 27 papers cited in narrative 27 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 8/8 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

MMP20 (enamelysin) is a secreted, zinc-dependent matrix metalloproteinase expressed by secretory-stage ameloblasts that drives enamel formation by stepwise proteolytic processing of the organic enamel matrix (PMID:9398237, PMID:19767579). It is a multidomain MMP with a signal peptide, latency-maintaining prodomain, catalytic zinc-binding domain, and hemopexin domain; catalysis depends on the conserved active-site histidine His226, whose substitution abolishes activity, while a hemopexin-domain mutation instead reduces protein stability without affecting catalysis (PMID:9398237, PMID:16246936, PMID:19966041). Its catalytic pocket favors substrates bearing large aromatic P1' residues (PMID:16548514). MMP20 cleaves the major enamel matrix proteins amelogenin and ameloblastin at defined sites that reproduce the secretory-stage fragments found in vivo (PMID:19767579, PMID:20400724), and this proteolysis is required to convert amorphous calcium phosphate into well-aligned hydroxyapatite crystals and to prevent aberrant crystal formation (PMID:27558264, PMID:30744480). MMP20 functions within a sequential protease cascade: its proform is activated by MT1-MMP, it in turn activates pro-KLK4, the maturation-stage successor protease, which then feeds back to inactivate MMP20, and the two enzymes act with overlapping/complementary roles in enamel hardening (PMID:12097451, PMID:24112721, PMID:27066511). Beyond matrix processing, MMP20 cleaves E- and N-cadherin extracellular domains, mobilizing β-catenin/Wnt signaling to govern ameloblast polarity and movement (PMID:24067343, PMID:29481294). MMP20 transcription is controlled by JNK/c-Jun (AP-1), TGF-β1/MEF2C, and ODAM/RUNX2 inputs (PMID:17611094, PMID:24495128, PMID:20665536). Loss of MMP20 in mice produces structurally defective, hypomineralized enamel, and amelogenin mutations that weaken MMP20 binding cause amelogenesis imperfecta (PMID:30744480, PMID:18434575, PMID:24072097).

Mechanistic history

Synthesis pass · year-by-year structured walk · 24 steps
  1. 1997 High

    Established MMP20 as a bona fide matrix metalloproteinase with defined domain architecture and intrinsic proteolytic activity against enamel matrix protein, answering whether the cloned gene encoded an active enzyme.

    Evidence cDNA cloning, recombinant E. coli expression and refolding, in vitro peptide and amelogenin degradation assays, chromosomal mapping to 11q22

    PMID:9398237

    Open questions at the time
    • In vivo physiological substrate repertoire not yet defined
    • Activation mechanism of the proform not addressed
  2. 2001 Medium

    Defined the broader ECM substrate selectivity of activated MMP20 and identified a candidate physiological activator, framing it as an enzyme with selective rather than promiscuous collagenolytic activity.

    Evidence Recombinant MMP-20 activation by trypsin-2 and in vitro degradation of multiple ECM proteins (fibronectin, type IV collagen, laminins, tenascin-C, β-casein; not type I/II collagen)

    PMID:11706946

    Open questions at the time
    • Physiological relevance of trypsin-2 activation in enamel uncertain
    • Non-enamel substrates not validated in vivo
  3. 2002 Medium

    Identified MT1-MMP as a physiological activator that converts proMMP-20 to active enzyme, resolving how MMP20 latency is relieved in dental tissue.

    Evidence Western blot of MT1-MMP forms in human odontoblasts plus in vitro proMMP-20 activation assay

    PMID:12097451

    Open questions at the time
    • Single activation method
    • Quantitative contribution of MT1-MMP versus other proteases in vivo unknown
  4. 2005 High

    Demonstrated that the conserved zinc-coordinating His226 is catalytically essential, pinpointing the active-site requirement for MMP20 function.

    Evidence Identification of p.H226Q mutation and zymogram comparison of mutant versus wild-type activity

    PMID:16246936

    Open questions at the time
    • Structural basis of substrate engagement not resolved
    • Disease association of this specific mutation not detailed here
  5. 2006 High

    Defined MMP20 substrate specificity (aromatic P1' preference), expanded its substrate set to type V collagen, and showed tooth-restricted expression with shared promoter modules, establishing it as a tooth-specific protease.

    Evidence Peptide library screen with Edman sequencing, collagen cleavage assay, mouse tissue expression survey, promoter analysis

    PMID:16548514

    Open questions at the time
    • Structural model of the catalytic pocket not solved
    • Functional role of type V collagen cleavage in enamel unclear
  6. 2007 High

    Identified MMP20 as the protease that processes ameloblastin at physiological sites, linking in vitro cleavage to the fragments concentrating in the secretory-stage sheath space.

    Evidence Recombinant AMBN and MMP-20 in vitro digestion with N-terminal sequencing, correlated with in vivo fragments

    PMID:17251515

    Open questions at the time
    • Functional consequence of each AMBN fragment not dissected
    • In vivo dependence on MMP20 not genetically tested here
  7. 2007 Medium

    Connected environmental and signaling control of MMP20 transcription by showing fluoride suppresses MMP20 via JNK/c-Jun and mapping functional AP-1 promoter sites.

    Evidence Fluoride treatment, Western blot, luciferase reporter, DNA-protein affinity precipitation, JNK activator in ameloblast lineage cells

    PMID:17611094

    Open questions at the time
    • In vivo contribution of AP-1 sites to enamel phenotype untested
    • Single cell-line system
  8. 2009 High

    Established MMP20 as the secretory-stage protease generating all major amelogenin fragments and distinguished its cleavage profile from that of KLK4.

    Evidence Native pig MMP-20 and KLK4 isolation, substrate digestion, LC-MS/MS, RP-HPLC, corroborated by in vivo fragments

    PMID:19767579

    Open questions at the time
    • Order/kinetics of sequential cleavages in vivo not fully resolved
  9. 2009 Medium

    Placed TGF-β1/TGFBR1 signaling upstream of MMP20 transcription, identifying a developmental signaling input specific to MMP20 over KLK4.

    Evidence Immunohistochemistry, RT-PCR, TGF-β1 treatment and constitutively active TGFBR1 transfection in ameloblast lineage cells

    PMID:19462458

    Open questions at the time
    • Direct promoter targets of TGF-β not defined here
    • In vivo requirement untested
  10. 2010 High

    Reinforced MMP20 as the in-vivo-relevant ameloblastin protease and identified ODAM/RUNX2 as a transcriptional regulatory axis that tunes MMP20 expression and amelogenin processing.

    Evidence In vitro AMBN digestion with MMP-20 versus KLK4 (idx 7); ODAM/RUNX2 gain- and loss-of-function with amelogenin processing assay (idx 8)

    PMID:20400724 PMID:20665536

    Open questions at the time
    • Direct ODAM/RUNX2 binding to the MMP20 promoter not shown
    • Crosstalk between regulatory pathways unresolved
  11. 2010 Medium

    Distinguished domain contributions to MMP20 function by showing the hemopexin-domain mutation p.A304T reduces protein expression/stability while preserving catalytic activity.

    Evidence Mutational analysis with Western blot and zymography

    PMID:19966041

    Open questions at the time
    • Mechanism of stability loss not defined
    • Single lab, two methods
  12. 2008 High

    Linked MMP20 substrate binding directly to disease by showing the amelogenesis imperfecta P41T amelogenin mutation reduces MMP20 binding and proteolysis.

    Evidence Substrate competition, pull-down, and surface plasmon resonance with wild-type and P41T amelogenin and recombinant MMP20

    PMID:18434575

    Open questions at the time
    • In vivo enamel phenotype of P41T not tested in this study
    • Binding interface not structurally mapped
  13. 2011 Medium

    Extended MMP20 function beyond matrix processing by showing it cleaves E-cadherin and influences ameloblast Tomes' process behavior, implicating cadherin/β-catenin signaling.

    Evidence Mmp20-null ameloblast morphology analysis plus in vitro E-cadherin cleavage assay

    PMID:21525715

    Open questions at the time
    • β-catenin nuclear release inferred, not directly demonstrated here
    • Cleavage site not mapped
  14. 2013 High

    Defined the MMP20–KLK4 protease cascade, establishing that MMP20 activates pro-KLK4 and KLK4 reciprocally inactivates MMP20, ordering the secretory-to-maturation transition.

    Evidence Native and recombinant MMP20/KLK4, zymography, RP-HPLC, Edman degradation of cleavage products

    PMID:24112721

    Open questions at the time
    • Spatiotemporal trigger that initiates the switch in vivo unknown
    • pH-dependence physiological significance not fully defined
  15. 2013 Medium

    Showed MMP20 cleaves both E- and N-cadherin and is required for the E-to-N cadherin switch, linking proteolysis to ameloblast row movement.

    Evidence In vitro cleavage assays plus qRT-PCR and immunostaining in Mmp20-null versus wild-type mice

    PMID:24067343

    Open questions at the time
    • Direct demonstration of β-catenin signaling output deferred
    • Causality versus correlation of transcript changes uncertain
  16. 2013 Medium

    Demonstrated that the mineral microenvironment and crystal binding modulate MMP20 activity and amelogenin accessibility, addressing how proteolysis is regulated within mineralizing enamel.

    Evidence In vitro digestions under varied calcium/phosphate conditions (idx 20); crystal occlusion assays with truncated amelogenin (idx 24)

    PMID:23201201 PMID:23226976

    Open questions at the time
    • In vivo ion gradients during amelogenesis not directly measured
    • Single-lab in vitro systems
  17. 2014 High

    Identified MEF2C as the transcription factor mediating TGF-β1 control of Mmp20, providing a direct promoter-level mechanism for the signaling input.

    Evidence MEF2C gain/loss-of-function, luciferase reporter, EMSA, ChIP, and promoter mutagenesis in ameloblast lineage cells

    PMID:24495128

    Open questions at the time
    • Integration with AP-1 and RUNX2 inputs not resolved
    • In vivo requirement of the MEF2 site untested
  18. 2014 Medium

    Showed MMP20 preferentially degrades hydroxyapatite-bound amelogenin, indicating its role in removing crystal-associated matrix to permit mineral growth.

    Evidence In vitro digestion of HAP-adsorbed versus solution amelogenin with spectrophotometry, SDS-PAGE, HPLC, LC-MALDI MS/MS

    PMID:25104939

    Open questions at the time
    • Physiological crystal surface context only partially mimicked
    • Single-lab in vitro system
  19. 2016 Medium

    Established that MMP20 proteolysis of amelogenin is required to convert amorphous calcium phosphate into aligned hydroxyapatite, defining its mechanistic role in crystal nucleation/organization.

    Evidence In vitro mineralization assay with/without recombinant MMP20, gel time-course, TEM

    PMID:27558264

    Open questions at the time
    • In vivo recapitulation of the ACP-to-HA dependence not shown in this study
    • Quantitative kinetics of transformation undefined
  20. 2018 High

    Demonstrated that MMP20 dosage controls ameloblast polarity and migration through Wnt/β-catenin signaling, connecting cadherin cleavage to a defined signaling output and pathological consequence of overexpression.

    Evidence MMP20-overexpressing transgenic mice, micro-CT, immunoblot, TOPflash reporter, Matrigel invasion, ICG-001 inhibition

    PMID:29481294

    Open questions at the time
    • Endogenous physiological β-catenin signaling level not quantified
    • Link from cadherin cleavage to β-catenin not directly traced in vivo
  21. 2019 High

    Showed MMP20 proteolysis is dose-dependently required to prevent aberrant octacalcium phosphate crystal formation, refining its role from simple matrix removal to active control of crystal phase.

    Evidence TEM, selected area electron diffraction, Raman microspectroscopy across Mmp20 KO, HET, WT enamel

    PMID:30744480

    Open questions at the time
    • Molecular signal coupling proteolysis to crystal phase selection unknown
  22. 2016 High

    Established genetic epistasis between MMP20 and KLK4 in enamel mineralization, showing additive loss and digenic heterozygous fragility consistent with overlapping protease function.

    Evidence Micro-CT, backscattered SEM, EDX across Mmp20-/-, Klk4-/-, double-null, and compound heterozygous mice

    PMID:27066511

    Open questions at the time
    • Molecular basis of digenic fragility not resolved
    • Stage-specific contributions not separated
  23. 2013 Medium

    Demonstrated via genetic rescue that MMP20 processing of M180 amelogenin is required for normal enamel hardness and decussating prism architecture.

    Evidence M180Tg/AmelxKO/Mmp20KO transgenic mice, SEM, micro-CT, nanoindentation

    PMID:24072097

    Open questions at the time
    • Specific cleavage products responsible for prism patterning not isolated
    • Single-lab rescue model
  24. 2025 Low

    Proposed DLX3 as a cell-autonomous transcriptional requirement for MMP20 expression in maturing ameloblasts, adding a developmental regulator to the MMP20 transcriptional network.

    Evidence iPSC-derived ameloblast organoids with DLX3 loss of function under Notch-agonist maturation (preprint)

    PMID:bio_10.1101_2025.04.03.646929

    Open questions at the time
    • Preprint, not peer-reviewed
    • Single method and system
    • Direct DLX3 binding to the MMP20 promoter not shown

Open questions

Synthesis pass · forward-looking unresolved questions
  • How the multiple transcriptional inputs (AP-1, TGF-β1/MEF2C, ODAM/RUNX2, DLX3) are integrated, and how proteolytic activity is spatiotemporally coordinated with the mineral environment to control crystal phase, remains unresolved.
  • No structural model of the MMP20 catalytic pocket
  • Integration of competing transcriptional regulators undefined
  • Mechanism coupling proteolysis to crystal phase selection unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0140096 catalytic activity, acting on a protein 7 GO:0016787 hydrolase activity 4 GO:0140097 catalytic activity, acting on DNA 3
Localization
GO:0005576 extracellular region 4 GO:0031012 extracellular matrix 3
Pathway
R-HSA-1266738 Developmental Biology 4 R-HSA-1474244 Extracellular matrix organization 3 R-HSA-392499 Metabolism of proteins 2
Partners
AMBNAMELXCDH1CDH2KLK4MMP14

Evidence

Reading pass · 27 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1997 Human MMP20 (enamelysin) was cloned from odontoblastic cells and shown to be a ~54 kDa matrix metalloproteinase with signal peptide, prodomain (PRCGVPD motif maintaining latency), catalytic zinc-binding domain, and hemopexin domain. Recombinant protein expressed in E. coli and refolded degraded synthetic MMP substrates and amelogenin, confirming proteolytic activity. The MMP20 gene maps to chromosome 11q22. cDNA cloning, recombinant protein expression in E. coli, in vitro peptide substrate degradation assay, amelogenin degradation assay, chromosomal mapping Biochemistry High 9398237
2005 A missense mutation in the MMP20 active site (p.H226Q, substituting the conserved catalytic zinc-coordinating histidine) completely abolishes MMP20 proteolytic activity, demonstrating that His226 is essential for catalysis. Site-specific mutation identification, zymogram analysis of mutant vs. wild-type MMP20 proteolytic activity Journal of dental research High 16246936
2006 MMP20 has a deep, wide catalytic pocket that preferentially accommodates substrates with large aromatic residues at the P1' position (unique among MMPs screened). Using iterative peptide library screening, type V collagen was identified and confirmed as an MMP20 substrate. MMP20 expression in non-dental tissues is restricted to trace amounts in large intestine, and four promoter modules shared with co-regulated tooth-specific genes (ameloblastin, amelogenin, enamelin) were identified. Mixture-based random dodecamer peptide library screen with Edman sequencing, in vitro collagen substrate cleavage assay, systematic mouse tissue expression screen, promoter cloning and in silico analysis Biochemistry High 16548514
2007 MMP20 cleaves ameloblastin (AMBN) at specific sites: after Pro2, Gln130, Gln139, Arg170, and Ala222 of porcine AMBN. This generates the 23-kDa AMBN fragment starting at Tyr223, and the 17-kDa (Val1-Arg170) and 15-kDa (Val1-Gln130) cleavage products that concentrate in the sheath space during the secretory stage, establishing MMP20 as the protease that processes ameloblastin in vitro and in vivo. Recombinant protein expression (glycosylated AMBN in HEK293F cells, MMP-20 in bacteria), in vitro digestion, N-terminal sequencing of cleavage products Journal of dental research High 17251515
2007 Fluoride exposure down-regulates MMP-20 protein and mRNA expression in human ameloblast lineage cells via suppression of JNK/c-Jun phosphorylation. Three c-Jun (AP-1) binding sites on the MMP20 promoter were identified and shown to be occupied by c-Jun during MMP20 induction; deletion of any single AP-1 site significantly reduced MMP20 promoter-driven transcription. Cell culture fluoride treatment, Western blot, luciferase reporter gene assay, DNA-protein affinity precipitation, JNK activator treatment Matrix biology Medium 17611094
2009 MMP-20 processes amelogenin exclusively during the secretory stage of amelogenesis by cleaving at specific sites (after Pro162, Ser148, His62, Ala63, and Trp45), generating all major cleavage products that accumulate in porcine secretory-stage enamel (23-, 20-, 13-, 11-, and 6-kDa amelogenins) as well as LRAP products. KLK4 could only replicate the cleavage after His62 among these key sites. Isolation of native pig MMP-20 and KLK4 from developing teeth, digestion of TRAP/LRAP and fluorescence peptides, LC-MSMS, SDS-PAGE, RP-HPLC Journal of dental research High 19767579
2009 TGF-β1 and its receptor TGFBR1 are expressed in secreting ameloblasts and specifically up-regulate MMP20 mRNA expression (but not KLK4) in ameloblast lineage cells in vitro. Overexpression of constitutively active TGFBR1 also promotes MMP20 expression, placing TGF-β signaling upstream of MMP20 transcriptional regulation. Immunohistochemistry, RT-PCR, TGF-β1 treatment of ameloblast lineage cells (ALC), activated TGFBR1 vector transfection Anatomical record Medium 19462458
2010 MMP-20 cleaves ameloblastin at six sites in vitro (matching in vivo cleavage sites), while KLK4 cleaves ameloblastin at sites not observed in vivo except a single correct site (before Leu171). This establishes MMP-20 as the enzyme responsible for processing ameloblastin during the secretory stage of amelogenesis. Isolation and purification of secretory-stage ameloblastin, in vitro digestion with MMP-20 and KLK4, N-terminal sequencing, SDS-PAGE, Western blot, fluorescent peptide RP-HPLC and mass spectrometry Journal of dental research High 20400724
2010 Nuclear ODAM cooperates with RUNX2 to regulate MMP-20 expression. Increased ODAM and RUNX2 co-expression augments MMP-20 expression; loss of RUNX2 decreases ODAM and MMP-20 expression. Increased MMP-20 expression in turn accelerates amelogenin processing during enamel mineralization. Subcellular localization analysis of ODAM by immunostaining, overexpression and knockdown of RUNX2/ODAM in ameloblast lineage cells (ALC), RT-PCR, Western blot, amelogenin processing assay Journal of cellular biochemistry Medium 20665536
2001 Activated recombinant MMP-20 does not degrade type I or type II collagen but efficiently hydrolyzes fibronectin, type IV collagen, laminin-1 and -5, tenascin-C, and β-casein. MMP-20 latent proform can be converted to active form by tumor-related trypsin-2. Recombinant MMP-20 expression, activation by trypsin-2, in vitro substrate degradation assays with various ECM proteins Journal of dental research Medium 11706946
2002 MT1-MMP (MMP-14) activates proMMP-20, converting it to a form corresponding to active MMP-20, as demonstrated in human odontoblast/pulp tissue systems. Western blot analysis of MT1-MMP forms in human odontoblasts, in vitro activation of proMMP-20 by MT1-MMP Journal of dental research Medium 12097451
2008 MMP-20 binds amelogenin directly, and the P41T amelogenin mutation (causing amelogenesis imperfecta) significantly reduces binding affinity of amelogenin for MMP20, leading to decreased proteolytic degradation of the mutant amelogenin. Substrate competition assay, pull-down assay, surface plasmon resonance (SPR) with recombinant wild-type and P41T mutant amelogenin vs. recombinant human MMP20 Journal of dental research High 18434575
2011 MMP20 cleaves E-cadherin extracellular domain. In Mmp20-null mice, secretory-stage ameloblasts show abnormal retraction and re-extension of Tomes' processes, suggesting MMP20-mediated cadherin cleavage influences ameloblast developmental progression. Cadherin cleavage by MMP20 may release β-catenin for nuclear translocation as a transcription factor. Analysis of Mmp20-null mouse ameloblast morphology, in vitro MMP20 cleavage assay of E-cadherin Cells, tissues, organs Medium 21525715
2013 MMP20 cleaves the extracellular domains of both E-cadherin and N-cadherin. In Mmp20-null mice, E- and N-cadherin transcripts are expressed at significantly higher levels, and high-level N-cadherin expression persists abnormally into the maturation stage. An E- to N-cadherin switch occurs from pre-secretory to secretory stage in wild-type ameloblasts, suggesting MMP20-mediated cadherin cleavage facilitates ameloblast row movement. In vitro MMP20 cleavage assay of E- and N-cadherin, qRT-PCR of cadherin expression in Mmp20-null vs. wild-type mice, immunostaining Journal of dental research Medium 24067343
2013 MMP20 activates proKLK4 by cleaving at the propeptide-enzyme junction used in vivo. Conversely, KLK4 inactivates MMP20 under physiologic (but not mildly acidic) conditions by cleaving principally at two sites in the MMP20 catalytic domain. This establishes a sequential protease cascade in which MMP20 activates its successor KLK4, which then feeds back to inactivate MMP20. Isolation of native pig MMP20 and KLK4 from developing teeth, recombinant human enzymes, zymography, RP-HPLC isolation, Edman degradation of cleavage products Archives of oral biology High 24112721
2014 Amelogenin adsorbed onto hydroxyapatite (HAP) crystals is hydrolyzed by MMP20 at a significantly higher rate than amelogenin in solution, and more cleavage sites are accessible. MMP20 releases ~88% of HAP-bound amelogenin into solution, suggesting preferential proteolytic removal of crystal-bound matrix protein. In vitro digestion of HAP-adsorbed vs. solution amelogenin by MMP20/KLK4, spectrophotometry, SDS-PAGE, HPLC, LC-MALDI MS/MS Frontiers in physiology Medium 25104939
2014 MEF2C acts as a transcription factor downstream of TGF-β1 to regulate Mmp20 gene expression in ameloblast lineage cells. A TGF-β1/MEF2C-responsive region containing a MEF2-binding site between bp -356 and -73 of the Mmp20 promoter was identified; mutation of this site significantly reduces Mmp20 promoter activity. MEF2C overexpression induces Mmp20 expression in a dose-dependent manner, and MEF2C knockdown blocks TGF-β1-induced Mmp20 expression. MEF2C overexpression and knockdown in ALC, luciferase reporter assay, EMSA, chromatin immunoprecipitation (ChIP), promoter deletion/mutation analysis European journal of oral sciences High 24495128
2016 MMP20 proteolysis of full-length native amelogenin (P173) generates P148 and other fragments, promoting formation of well-aligned bundles of enamel-like hydroxyapatite crystals from amorphous calcium phosphate (ACP) precursors in vitro. MMP20 does not cleave P148. Absence of MMP20-mediated proteolysis results in only ACP formation, establishing that amelogenin proteolysis by MMP20 is required for ACP-to-HA crystal transformation. In vitro calcium phosphate mineralization assay with/without recombinant MMP20, gel electrophoresis time-course, transmission electron microscopy (TEM) Journal of dental research Medium 27558264
2018 MMP20 overexpression in transgenic mice causes premature cleavage of ameloblastin (AMBN), disruption of ameloblast polarity (increased inactive p-cofilin), and pathological migration of ameloblasts away from the enamel layer into the stratum intermedium via the Wnt/β-catenin pathway. TOPflash assays in vitro demonstrated that MMP20 expression promotes β-catenin nuclear localization and cell invasion through Matrigel, both of which are abolished by the β-catenin inhibitor ICG-001. MMP20-overexpressing transgenic mice, micro-CT, immunoblot, TOPflash β-catenin reporter assay, Matrigel invasion assay, β-catenin inhibitor (ICG-001) treatment Journal of dental research High 29481294
2019 MMP20 proteolysis of enamel matrix proteins is essential for preventing aberrant crystal formation during amelogenesis. In Mmp20-null mice, initial ACP-to-apatite crystal transformation proceeds normally, but large, randomly dispersed plate-like octacalcium phosphate crystals subsequently appear and dominate, halting enamel layer thickening. The severity is proportional to MMP20 expression level (KO > HET > WT). Transmission electron microscopy, selected area electron diffraction, Raman microspectroscopy on Mmp20-null, heterozygous, and wild-type mouse enamel sections Journal of dental research High 30744480
2013 Mineral ion composition modulates MMP-20 kinetics and cleavage pattern on amelogenin. MMP-20 is most active at high calcium concentration and slowest at high phosphate or combined high calcium/phosphate. The central region of amelogenin is relatively protected under high calcium/phosphate conditions. In vitro MMP-20 digestion of recombinant human amelogenin under varied mineral ion compositions, SDS-PAGE, MALDI-TOF MS Biochimica et biophysica acta Medium 23201201
2004 MMP-20 degrades collagen XVIII in vitro, and the two proteins are co-localized in developing enamel matrix and stratum intermedium. In vitro degradation assay of collagen XVIII by MMP-20, immunohistochemistry/co-localization, Western blotting of developing enamel Matrix biology Low 15296943
2015 In Mmp20-null mice, micro-CT reveals significantly reduced high-density enamel volume compared to wild-type. Mmp20-null enamel separates from dentin during development, and cells invade cracks between dentin and enamel layers. Double-null Mmp20/Klk4 mice show further reduction in enamel volume, and digenic heterozygous (Mmp20+/- Klk4+/-) mice exhibit unexpected enamel fracture, suggesting overlapping/complementary roles. Micro-CT, backscattered SEM, dissecting and light microscopy, energy-dispersive X-ray analysis on Mmp20-/-, Klk4-/-, double-null, and compound heterozygous mice Molecular genetics & genomic medicine High 27066511
2013 M180 amelogenin processed by MMP20 is sufficient for normal enamel mechanical properties and decussating prism pattern in mice. Loss of MMP20 in M180Tg/AmelxKO/Mmp20KO mice eliminates normal prismatic architecture and reduces enamel hardness to 37% of controls, demonstrating MMP20 processing of M180 amelogenin is required for proper enamel structure. Transgenic mouse generation (M180Tg/DKO), SEM, micro-CT, nanoindentation Journal of dental research Medium 24072097
2012 MMP-20 proteolysis of full-length amelogenin prevents occlusion of the protein inside calcite crystals by removing the C-terminal domain, which has the highest crystal-binding affinity. Truncated amelogenin (lacking C-terminus) produced by MMP-20 cleavage shows diminished crystal affinity and minimal occlusion. In vitro crystal growth in presence of rP172 amelogenin ± recombinant human MMP-20, crystal morphology analysis, protein occlusion measurement Crystal growth & design Medium 23226976
2010 MMP20 hemopexin domain mutation (p.A304T) results in decreased expression of the mutant protein by Western blot, but zymogram analysis demonstrates that the mutant retains proteolytic activity, establishing that the hemopexin domain affects protein stability/expression rather than catalytic activity. Mutational analysis, Western blot, zymogram analysis Journal of dental research Medium 19966041
2025 DLX3 is required cell-autonomously in ameloblasts for the expression of MMP20 (and Enamelin), as shown using iPSC-derived ameloblast organoids with DLX3 loss of function in a Notch-agonist-driven maturation system. iPSC-derived ameloblast organoid differentiation, Notch agonist treatment, DLX3 loss-of-function, RT-PCR/gene expression analysis bioRxivpreprint Low bio_10.1101_2025.04.03.646929

Source papers

Stage 0 corpus · 64 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
1999 Analysis of 16 different matrix metalloproteinases (MMP-1 to MMP-20) in the synovial membrane: different profiles in trauma and rheumatoid arthritis. Annals of the rheumatic diseases 342 10531073
2008 Functions of KLK4 and MMP-20 in dental enamel formation. Biological chemistry 196 18627287
1997 Identification and structural and functional characterization of human enamelysin (MMP-20). Biochemistry 179 9398237
2005 MMP20 active-site mutation in hypomaturation amelogenesis imperfecta. Journal of dental research 94 16246936
2009 Mmp-20 and Klk4 cleavage site preferences for amelogenin sequences. Journal of dental research 82 19767579
2002 Bisphosphonates inhibit stromelysin-1 (MMP-3), matrix metalloelastase (MMP-12), collagenase-3 (MMP-13) and enamelysin (MMP-20), but not urokinase-type plasminogen activator, and diminish invasion and migration of human malignant and endothelial cell lines. Anti-cancer drugs 82 11984068
2008 Human and mouse enamel phenotypes resulting from mutation or altered expression of AMEL, ENAM, MMP20 and KLK4. Cells, tissues, organs 71 18714142
2010 Pseudogenization of the tooth gene enamelysin (MMP20) in the common ancestor of extant baleen whales. Proceedings. Biological sciences 67 20861053
2007 Processing of ameloblastin by MMP-20. Journal of dental research 67 17251515
2012 Genetic variation in MMP20 contributes to higher caries experience. Journal of dentistry 64 22330321
2010 Cleavage site specificity of MMP-20 for secretory-stage ameloblastin. Journal of dental research 56 20400724
1999 Overview of expression of matrix metalloproteinases (MMP-17, MMP-18, and MMP-20) in cultured human cells. Matrix biology : journal of the International Society for Matrix Biology 56 10372554
2008 Premature stop codon in MMP20 causing amelogenesis imperfecta. Journal of dental research 55 18096894
2010 The odontogenic ameloblast-associated protein (ODAM) cooperates with RUNX2 and modulates enamel mineralization via regulation of MMP-20. Journal of cellular biochemistry 50 20665536
2000 Immunohistochemical detection and distribution of enamelysin (MMP-20) in human odontogenic tumors. Journal of dental research 49 11023283
2013 Novel KLK4 and MMP20 mutations discovered by whole-exome sequencing. Journal of dental research 47 23355523
2015 Analysis of the association between polymorphisms in MMP2, MMP3, MMP9, MMP20, TIMP1, and TIMP2 genes with white spot lesions and early childhood caries. International journal of paediatric dentistry 42 26371789
2010 MMP20 hemopexin domain mutation in amelogenesis imperfecta. Journal of dental research 40 19966041
2009 Sequential use of transcriptional profiling, expression quantitative trait mapping, and gene association implicates MMP20 in human kidney aging. PLoS genetics 39 19834535
2007 JNK/c-Jun signaling pathway mediates the fluoride-induced down-regulation of MMP-20 in vitro. Matrix biology : journal of the International Society for Matrix Biology 39 17611094
2015 MMP20, KLK4, and MMP20/KLK4 double null mice define roles for matrix proteases during dental enamel formation. Molecular genetics & genomic medicine 38 27066511
2014 Preferential and selective degradation and removal of amelogenin adsorbed on hydroxyapatites by MMP20 and KLK4 in vitro. Frontiers in physiology 37 25104939
2006 MMP-20 is predominately a tooth-specific enzyme with a deep catalytic pocket that hydrolyzes type V collagen. Biochemistry 35 16548514
2001 Expression and regulation of MMP-20 in human tongue carcinoma cells. Journal of dental research 35 11706946
2017 Common variants in MMP20 at 11q22.2 predispose to 11q deletion and neuroblastoma risk. Nature communications 33 28924153
2009 TGF-beta1 and TGFBR1 are expressed in ameloblasts and promote MMP20 expression. Anatomical record (Hoboken, N.J. : 2007) 33 19462458
2002 Regulation and interactions of MT1-MMP and MMP-20 in human odontoblasts and pulp tissue in vitro. Journal of dental research 32 12097451
2017 The Presence of MMP-20 Reinforces Biomimetic Enamel Regrowth. Journal of dental research 30 28846464
2013 Homozygous and compound heterozygous MMP20 mutations in amelogenesis imperfecta. Journal of dental research 28 23625376
2014 Extracts of irradiated mature human tooth crowns contain MMP-20 protein and activity. Journal of dentistry 26 24607847
2011 MMP20 cleaves E-cadherin and influences ameloblast development. Cells, tissues, organs 24 21525715
2016 Abrogation of epithelial BMP2 and BMP4 causes Amelogenesis Imperfecta by reducing MMP20 and KLK4 expression. Scientific reports 22 27146352
2015 MMP20 and ARMS2/HTRA1 Are Associated with Neovascular Lesion Size in Age-Related Macular Degeneration. Ophthalmology 22 26337002
2013 MMP20 modulates cadherin expression in ameloblasts as enamel develops. Journal of dental research 22 24067343
2011 Assessment of dental fluorosis in Mmp20 +/- mice. Journal of dental research 22 21386097
2004 Expression of collagen XVIII and MMP-20 in developing teeth and odontogenic tumors. Matrix biology : journal of the International Society for Matrix Biology 22 15296943
2016 MMP20 Proteolysis of Native Amelogenin Regulates Mineralization In Vitro. Journal of dental research 21 27558264
2018 MMP20 Overexpression Disrupts Molar Ameloblast Polarity and Migration. Journal of dental research 20 29481294
2016 MMP20 rs1784418 Protects Certain Populations against Caries. Caries research 20 27992873
2013 MMP20 and KLK4 activation and inactivation interactions in vitro. Archives of oral biology 20 24112721
2017 Analyses of MMP20 Missense Mutations in Two Families with Hypomaturation Amelogenesis Imperfecta. Frontiers in physiology 18 28473773
2010 MMP1 and MMP20 contribute to tooth agenesis in humans. Archives of oral biology 17 21144496
2019 Proteolysis by MMP20 Prevents Aberrant Mineralization in Secretory Enamel. Journal of dental research 15 30744480
2013 M180 amelogenin processed by MMP20 is sufficient for decussating murine enamel. Journal of dental research 15 24072097
2020 Effects of DSPP and MMP20 Silencing on Adhesion, Metastasis, Angiogenesis, and Epithelial-Mesenchymal Transition Proteins in Oral Squamous Cell Carcinoma Cells. International journal of molecular sciences 14 32630820
2018 DSPP-MMP20 gene silencing downregulates cancer stem cell markers in human oral cancer cells. Cellular & molecular biology letters 13 30002682
2008 Reduced amelogenin-MMP20 interactions in amelogenesis imperfecta. Journal of dental research 13 18434575
2015 Expression of Matrix Metalloproteinase (MMP)-20 and Potential Interaction with Dentin Sialophosphoprotein (DSPP) in Human Major Salivary Glands. The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society 12 25805840
2017 Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta. Frontiers in physiology 10 28659819
2016 Expression Pattern of Matrix Metalloproteinase 20 (MMP20) in Human Tumors. Anticancer research 10 27272780
2006 Identification and characterization of matrix metalloproteinase-20 (MMP20; enamelysin) genes in reptile and amphibian. Gene 10 17223283
2016 Mutations in MSX1, PAX9 and MMP20 genes in Saudi Arabian patients with tooth agenesis. European journal of medical genetics 9 27365112
2021 Spectrum of pathogenic variants and founder effects in amelogenesis imperfecta associated with MMP20. Human mutation 7 33600052
2019 DNA sequencing reveals AMELX, ODAM and MMP20 variations in dental fluorosis. Archives of oral biology 7 31838295
2014 Transforming growth factor-β1 regulates expression of the matrix metalloproteinase 20 (Mmp20) gene through a mechanism involving the transcription factor, myocyte enhancer factor-2C, in ameloblast lineage cells. European journal of oral sciences 6 24495128
2012 Amelogenin processing by MMP-20 prevents protein occlusion inside calcite crystals. Crystal growth & design 6 23226976
2000 One-step sandwich enzyme immunoassay using monoclonal antibodies for detection of human enamelysin (MMP-20). European journal of oral sciences 5 11153928
2021 Lung development, repair and cancer: A study on the role of MMP20 gene in adenocarcinoma. PloS one 4 33914777
2019 MMP20 Single-Nucleotide Polymorphisms Correlate with Susceptibility to Alcohol-Induced Osteonecrosis of the Femoral Head in Chinese Males. Medical science monitor : international medical journal of experimental and clinical research 4 31106781
2013 The proteolytic processing of amelogenin by enamel matrix metalloproteinase (MMP-20) is controlled by mineral ions. Biochimica et biophysica acta 4 23201201
2024 Proteolytic profiles of two isoforms of human AMBN expressed in E. coli by MMP-20 and KLK-4 proteases. Heliyon 3 38298721
2025 Analysis of MMP-8, MMP-20, and TGF-β1 in molar-incisor hypomineralization and assessment of periodontal health. BMC oral health 1 40676550
2024 Association between LTF/MMP20/CA6/TAS1R2 polymorphisms and susceptibility to dental caries. Clinical oral investigations 1 39212776
2025 Expression of AMELX, AMBN, ENAM, TUFT1, FAM83H and MMP20 Genes in Buccal Epithelial Cells from Patients with Molar Incisor Hypomineralization (MIH)-A Pilot Study. International journal of molecular sciences 0 39859478

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