1
|
Kawasaki K, Sasagawa I, Mikami M, Nakatomi M, Ishiyama M. Ganoin and acrodin formation on scales and teeth in spotted gar: A vital role of enamelin in the unique process of enamel mineralization. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2023; 340:455-468. [PMID: 36464775 PMCID: PMC10239528 DOI: 10.1002/jez.b.23183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/12/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022]
Abstract
Gars and bichirs develop scales and teeth with ancient actinopterygian characteristics. Their scale surface and tooth collar are covered with enamel, also known as ganoin, whereas the tooth cap is equipped with an enamel-like tissue, acrodin. Here, we investigated the formation and mineralization of the ganoin and acrodin matrices in spotted gar, and the evolution of the scpp5, ameloblastin (ambn), and enamelin (enam) genes, which encode matrix proteins of ganoin. Results suggest that, in bichirs and gars, all these genes retain structural characteristics of their orthologs in stem actinopterygians, presumably reflecting the presence of ganoin on scales and teeth. During scale formation, Scpp5 and Enam were initially found in the incipient ganoin matrix and the underlying collagen matrix, whereas Ambn was detected mostly in a surface region of the well-developed ganoin matrix. Although collagen is the principal acrodin matrix protein, Scpp5 was detected within the matrix. Similarities in timings of mineralization and the secretion of Scpp5 suggest that acrodin evolved by the loss of the matrix secretory stage of ganoin formation: dentin formation is immediately followed by the maturation stage. The late onset of Ambn secretion during ganoin formation implies that Ambn is not essential for mineral ribbon formation, the hallmark of the enamel matrix. Furthermore, Scpp5 resembles amelogenin that is not important for the initial formation of mineral ribbons in mammals. It is thus likely that the evolution of ENAM was vital to the origin of the unique mineralization process of the enamel matrix.
Collapse
Affiliation(s)
- Kazuhiko Kawasaki
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Ichiro Sasagawa
- Advanced Research Center, School of Life Dentistry at Niigata the Nippon Dental University, Niigata, Japan
| | - Masato Mikami
- Department of Microbiology, School of Life Dentistry at Niigata the Nippon Dental University, Niigata, Japan
| | - Mitsushiro Nakatomi
- Department of Human, Information and Life Sciences, School of Health Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Mikio Ishiyama
- Department of Histology, School of Life Dentistry at Niigata the Nippon Dental University, Niigata, Japan
| |
Collapse
|
2
|
Khami MR, Asgari S, Valizadeh S, Karami J, Rezaei A, Rezaei N. AMELX and ENAM Polymorphisms and Dental Caries. Int J Dent 2022; 2022:8501179. [PMID: 36624859 PMCID: PMC9825226 DOI: 10.1155/2022/8501179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 12/01/2022] [Accepted: 12/19/2022] [Indexed: 01/02/2023] Open
Abstract
Introduction The variety of the genetic factors playing role in development of dental caries calls for further research in this regard. The aim of the present study was to investigate the differences between caries-free adults and adults with dental caries in terms of polymorphism of caries-related genes (AMELX and ENAM). Methods The present case-control study was performed on 81 adults aged 18-24 years, 41 caries free, and 40 with a DMFT ≥ 4. A questionnaire containing background and demographic information (such as age, gender, time and type of latest dental check-ups, parent's education, oral self-care, and the place of residence in the first 12 years of life) was completed by participants at the time of examination. The blood sample was taken from each participant in the EDTA tube, and PCR was performed. Gene diversity of AMELX and ENAM genes was compared between the two groups. Results Regarding AMELX gene, in the caries-free group 33 (80.5%) and in the group with DMFT ≥ 4, 33 (82.5%) students had TT genotype, but this difference was insignificant. For ENAM gene, in the caries-free group 34 (82.9%) and in the group with DMFT ≥ 4, 39 (97.5%) students had TT genotype, but this difference was insignificant (P value = 0.048, CI 95%:0.02-1.27, and OR = 0.145). Conclusion There was no relationship between TT and TC genotypes of single nucleotide polymorphism of AMELX and ENAM gene and susceptibility to dental caries, but with increasing sample size, there may be a relationship between SNP of ENAM gene and being caries free.
Collapse
Affiliation(s)
- Mohammad Reza Khami
- Research Center for Caries Prevention Dentistry Research, Institute Community Oral Health Department, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Sahar Asgari
- Department of Periodontology, School of Dentistry, Babol University of Medical Sciences, Babol, Iran
| | - Sara Valizadeh
- Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Jafar Karami
- Molecular and Medicine Research Center, Khomein University of Medical Sciences, Khomein, Iran
| | - Arezou Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Nima Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA) Universal Scientific Education and Research Network (USERN), Tehran, Iran
| |
Collapse
|
3
|
Thampan N, Ramya R, Swarnalakshmi R, Rajkumar K, Savithri S, Divyalakshmi G. Analysis of ENAM gene single-nucleotide polymorphism rs3796704 with caries susceptibility in young adult Tamil population. J Oral Maxillofac Pathol 2021; 25:226-231. [PMID: 34703114 PMCID: PMC8491349 DOI: 10.4103/0973-029x.325119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/16/2022] Open
Abstract
Background: Dental caries is as primeval as humanity, but still, investigations are undergoing regarding the etiopathogenesis behind this multifactorial disease. Genetics is known to play a vital role in the etiology behind dental caries in addition to environmental and socioeconomic factors. Genetic variations like single-nucleotide polymorphisms (SNPs) were extensively studied in the past decade to portray the etiopathogenesis contributing to dental caries. Aim: This investigation was undertaken to analyze the ENAM gene SNP rs3796704 with caries susceptibility in ethnic young adult Tamil population of India. Materials and Methods: Out of 370 patients included, 215 patients belonged to the high caries group (Decayed, Missing and Filled Tooth [DMFT] ≥2) and 155 patients belonged to the low caries group (DMFT ≤ 1). DNA was extracted from the blood of all the individuals. SNP genotyping was performed utilizing tetra-primer amplification refractory mutation system–polymerase chain reaction with specific primers. Results: The genotyping results showed that there were no differences in allelic (P = 0.114) and genotypic frequencies (P = 0.159) between the high caries and low caries groups. Conclusion: Future studies can be conducted in larger samples and different ethnicities around the globe to analyze the role played by SNPs of enamel formation genes in cariogenesis.
Collapse
Affiliation(s)
- Niveditha Thampan
- Department of Oral and Maxillofacial Pathology, SRM Dental College, Chennai, Tamil Nadu, India
| | - R Ramya
- Department of Oral and Maxillofacial Pathology, Saveetha Dental College, Chennai, Tamil Nadu, India
| | - R Swarnalakshmi
- Department of Stomatognathic Function and Occlusal Reconstruction, Tokushima University, Tokushima, Japan
| | - K Rajkumar
- Department of Oral and Maxillofacial Pathology, SRM Dental College, Chennai, Tamil Nadu, India
| | - S Savithri
- Department of Microbiology, SRM Dental College, Chennai, Tamil Nadu, India
| | - G Divyalakshmi
- Department of Oral and Maxillofacial Pathology, SRM Dental College, Chennai, Tamil Nadu, India
| |
Collapse
|
4
|
Molecular Evolution of Tooth-Related Genes Provides New Insights into Dietary Adaptations of Mammals. J Mol Evol 2021; 89:458-471. [PMID: 34287664 PMCID: PMC8318974 DOI: 10.1007/s00239-021-10017-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 06/10/2021] [Indexed: 11/01/2022]
Abstract
Mammals have evolved different tooth phenotypes that are hypothesized to be associated with feeding habits. However, the genetic basis for the linkage has not been well explored. In this study, we investigated 13 tooth-related genes, including seven enamel-related genes (AMELX, AMBN, ENAM, AMTN, ODAM, KLK4 and MMP20) and six dentin-related genes (DSPP, COL1A1, DMP1, IBSP, MEPE and SPP1), from 63 mammals to determine their evolutionary history. Our results showed that different evolutionary histories have evolved among divergent feeding habits in mammals. There was stronger positive selection for eight genes (ENAM, AMTN, ODAM, KLK4, DSPP, DMP1, COL1A1, MEPE) in herbivore lineages. In addition, AMELX, AMBN, ENAM, AMTN, MMP20 and COL1A1 underwent accelerated evolution in herbivores. While relatively strong positive selection was detected in IBSP, SPP1, and DSPP, accelerated evolution was only detected for MEPE and SPP1 genes among the carnivorous lineages. We found positive selection on AMBN and ENAM genes for omnivorous primates in the catarrhini clade. Interestingly, a significantly positive association between the evolutionary rate of ENAM, ODAM, KLK4, MMP20 and the average enamel thickness was found in primates. Additionally, we found molecular convergence in some amino acid sites of tooth-related genes among the lineages whose feeding habit are similar. The positive selection of related genes might promote the formation and bio-mineralization of tooth enamel and dentin, which would make the tooth structure stronger. Our results revealed that mammalian tooth-related genes have experienced variable evolutionary histories, which provide some new insights into the molecular basis of dietary adaptation in mammals.
Collapse
|
5
|
Sharifi R, Jahedi S, Mozaffari HR, Imani MM, Sadeghi M, Golshah A, Moradpoor H, Safaei M. Association of LTF, ENAM, and AMELX polymorphisms with dental caries susceptibility: a meta-analysis. BMC Oral Health 2020; 20:132. [PMID: 32375748 PMCID: PMC7204276 DOI: 10.1186/s12903-020-01121-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 04/27/2020] [Indexed: 12/22/2022] Open
Abstract
Background This meta-analysis evaluated the association of LTF, ENAM, and AMELX polymorphisms with dental caries susceptibility. Methods We searched the Scopus, PubMed/Medline, Web of Science, and Cochrane Library databases to retrieve articles published by October 2019. Review Manager 5.3 software was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). The results of publication bias tests were retrieved by Comprehensive Meta-Analysis 2.0 software. Results A total of 150 relevant records were identified; out of which, 16 were entered into the analysis (4 studies assessed LTF, 11 ENAM, and 11 AMELX polymorphisms). Of all polymorphisms, there was a significant association only between ENAM rs3796704 polymorphism and dental caries susceptibility. Both ENAM rs3796704 and AMELX rs17878486 polymorphisms had a significant association with dental caries risk in the Caucasian ethnicity and the studies including caries-free control group. Conclusions The results of this meta-analysis showed that the G allele and the GG genotype of ENAM rs3796704 were associated with an increased risk of caries in the case group compared with the control group. But there was no association between LTF rs1126478, ENAM (rs1264848 and rs3796703), and AMELX (rs946252, rs17878486, and rs2106416) polymorphisms and dental caries susceptibility.
Collapse
Affiliation(s)
- Roohollah Sharifi
- Department of Endodontics, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, 6713954658, Iran
| | - Sajjad Jahedi
- Students Research Committee, Kermanshah University of Medical Sciences, Kermanshah, 6715847141, Iran
| | - Hamid Reza Mozaffari
- Department of Oral and Maxillofacial Medicine, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, 6713954658, Iran
| | - Mohammad Moslem Imani
- Department of Orthodontics, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, 6713954658, Iran
| | - Masoud Sadeghi
- Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, 6714415185, Iran.
| | - Amin Golshah
- Department of Orthodontics, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, 6713954658, Iran
| | - Hedaiat Moradpoor
- Department of Prosthodontics, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, 6713954658, Iran
| | - Mohsen Safaei
- Advanced Dental Sciences Research Laboratory, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, 6713954658, Iran
| |
Collapse
|
6
|
Zhang H, Hu Y, Seymen F, Koruyucu M, Kasimoglu Y, Wang S, Wright JT, Havel MW, Zhang C, Kim J, Simmer JP, Hu JC. ENAM mutations and digenic inheritance. Mol Genet Genomic Med 2019; 7:e00928. [PMID: 31478359 PMCID: PMC6785452 DOI: 10.1002/mgg3.928] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND ENAM mutations cause autosomal dominant or recessive amelogenesis imperfecta (AI) and show a dose effect: enamel malformations are more severe or only penetrant when both ENAM alleles are defective. METHODS Whole exome sequences of recruited AI probands were initially screened for mutations in known AI candidate genes. Sanger sequencing was used to confirm sequence variations and their segregation with the disease phenotype. The co-occurrence of ENAM and LAMA3 mutations in one family raised the possibility of digenic inheritance. Enamel formed in Enam+/+ Ambn+/+ , Enam+/- , Ambn+/- , and Enam+/- Ambn+/- mice was characterized by dissection and backscattered scanning electron microscopy (bSEM). RESULTS ENAM mutations segregating with AI in five families were identified. Two novel ENAM frameshift mutations were identified. A single-nucleotide duplication (c.395dupA/p.Pro133Alafs*13) replaced amino acids 133-1142 with a 12 amino acid (ATTKAAFEAAIT*) sequence, and a single-nucleotide deletion (c.2763delT/p.Asp921Glufs*32) replaced amino acids 921-1142 with 31 amino acids (ESSPQQASYQAKETAQRRGKAKTLLEMMCPR*). Three families were heterozygous for a previously reported single-nucleotide ENAM deletion (c.588+1delG/p.Asn197Ilefs*81). One of these families also harbored a heterozygous LAMA3 mutation (c.1559G>A/p.Cys520Tyr) that cosegregated with both the AI phenotype and the ENAM mutation. In mice, Ambn+/- maxillary incisors were normal. Ambn+/- molars were also normal, except for minor surface roughness. Ambn+/- mandibular incisors were sometimes chalky and showed minor chipping. Enam+/- incisor enamel was thinner than normal with ectopic mineral deposited laterally. Enam+/- molars were sometimes chalky and rough surfaced. Enam+/- Ambn+/- enamel was thin and rough, in part due to ectopic mineralization, but also underwent accelerated attrition. CONCLUSION Novel ENAM mutations causing AI were identified, raising to 22 the number of ENAM variations known to cause AI. The severity of the enamel phenotype in Enam+/- Ambn+/- double heterozygous mice is caused by composite digenic effects. Digenic inheritance should be explored as a cause of AI in humans.
Collapse
Affiliation(s)
- Hong Zhang
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Yuanyuan Hu
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Figen Seymen
- Department of Pedodontics, Faculty of DentistryIstanbul UniversityIstanbulTurkey
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of DentistryIstanbul UniversityIstanbulTurkey
| | - Yelda Kasimoglu
- Department of Pedodontics, Faculty of DentistryIstanbul UniversityIstanbulTurkey
| | - Shih‐Kai Wang
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
- Department of DentistryNational Taiwan University School of DentistryTaipei CityTaiwan R.O.C.
| | - John Timothy Wright
- Department of Pediatric DentistryUniversity of North Carolina School of DentistryChapel HillNCUSA
| | - Michael W. Havel
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Chuhua Zhang
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Jung‐Wook Kim
- Department of Molecular Genetics and Department of Pediatric Dentistry and Dental Research Institute, School of DentistrySeoul National UniversitySeoulKorea
| | - James P. Simmer
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| | - Jan C.‐C. Hu
- Department of Biologic and Materials SciencesUniversity of Michigan School of DentistryAnn ArborMIUSA
| |
Collapse
|
7
|
Green DR, Schulte F, Lee KH, Pugach MK, Hardt M, Bidlack FB. Mapping the Tooth Enamel Proteome and Amelogenin Phosphorylation Onto Mineralizing Porcine Tooth Crowns. Front Physiol 2019; 10:925. [PMID: 31417410 PMCID: PMC6682599 DOI: 10.3389/fphys.2019.00925] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/09/2019] [Indexed: 01/13/2023] Open
Abstract
Tooth enamel forms in an ephemeral protein matrix where changes in protein abundance, composition and posttranslational modifications are critical to achieve healthy enamel properties. Amelogenin (AMELX) with its splice variants is the most abundant enamel matrix protein, with only one known phosphorylation site at serine 16 shown in vitro to be critical for regulating mineralization. The phosphorylated form of AMELX stabilizes amorphous calcium phosphate, while crystalline hydroxyapatite forms in the presence of the unphosphorylated protein. While AMELX regulates mineral transitions over space and time, it is unknown whether and when un-phosphorylated amelogenin occurs during enamel mineralization. This study aims to reveal the spatiotemporal distribution of the cleavage products of the most abundant AMLEX splice variants including the full length P173, the shorter leucine-rich amelogenin protein (LRAP), and the exon 4-containing P190 in forming enamel, all within the context of the changing enamel matrix proteome during mineralization. We microsampled permanent pig molars, capturing known stages of enamel formation from both crown surface and inner enamel. Nano-LC-MS/MS proteomic analyses after tryptic digestion rendered more than 500 unique protein identifications in enamel, dentin, and bone. We mapped collagens, keratins, and proteolytic enzymes (CTSL, MMP2, MMP10) and determined distributions of P173, LRAP, and P190 products, the enamel proteins enamelin (ENAM) and ameloblastin (AMBN), and matrix-metalloprotease-20 (MMP20) and kallikrein-4 (KLK4). All enamel proteins and KLK4 were near-exclusive to enamel and in excellent agreement with published abundance levels. Phosphorylated P173 and LRAP products decreased in abundance from recently deposited matrix toward older enamel, mirrored by increasing abundances of testicular acid phosphatase (ACPT). Our results showed that hierarchical clustering analysis of secretory enamel links closely matching distributions of unphosphorylated P173 and LRAP products with ACPT and non-traditional amelogenesis proteins, many associated with enamel defects. We report higher protein diversity than previously published and Gene Ontology (GO)-defined protein functions related to the regulation of mineral formation in secretory enamel (e.g., casein α-S1, CSN1S1), immune response in erupted enamel (e.g., peptidoglycan recognition protein, PGRP), and phosphorylation. This study presents a novel approach to characterize and study functional relationships through spatiotemporal mapping of the ephemeral extracellular matrix proteome.
Collapse
Affiliation(s)
- Daniel R Green
- The Forsyth Institute, Cambridge, MA, United States.,Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, United States
| | | | - Kyu-Ha Lee
- The Forsyth Institute, Cambridge, MA, United States.,Department of Oral Health Policy and Epidemiology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Megan K Pugach
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Markus Hardt
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Felicitas B Bidlack
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
| |
Collapse
|
8
|
Alazem O, Abramyan J. Reptile enamel matrix proteins: Selection, divergence, and functional constraint. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2019; 332:136-148. [PMID: 31045323 DOI: 10.1002/jez.b.22857] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 02/24/2019] [Accepted: 04/01/2019] [Indexed: 12/14/2022]
Abstract
The three major enamel matrix proteins (EMPs): amelogenin (AMEL), ameloblastin (AMBN), and enamelin (ENAM), are intrinsically linked to tooth development in tetrapods. However, reptiles and mammals exhibit significant differences in dental patterning and development, potentially affecting how EMPs evolve in each group. In most reptiles, teeth are replaced continuously throughout life, while mammals have reduced replacement to only one or two generations. Reptiles also form structurally simple, aprismatic enamel while mammalian enamel is composed of highly organized hydroxyapatite prisms. These differences, combined with reported low sequence homology in reptiles, led us to predict that reptiles may experience lower selection pressure on their EMPs as compared with mammals. However, we found that like mammals, reptile EMPs are under moderate purifying selection, with some differences evident between AMEL, AMBN, and ENAM. We also demonstrate that sequence homology in reptile EMPs is closely associated with divergence times, with more recently diverged lineages exhibiting high homology, along with strong phylogenetic signal. Lastly, despite sequence divergence, none of the reptile species in our study exhibited mutations consistent with diseases that cause degeneration of enamel (e.g. amelogenesis imperfecta). Despite short tooth retention time and simplicity in enamel structure, reptile EMPs still exhibit purifying selection required to form durable enamel.
Collapse
Affiliation(s)
- Omar Alazem
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan
| | - John Abramyan
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan
| |
Collapse
|
9
|
Towle I, Irish JD. A probable genetic origin for pitting enamel hypoplasia on the molars of Paranthropus robustus. J Hum Evol 2019; 129:54-61. [DOI: 10.1016/j.jhevol.2019.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 01/03/2019] [Accepted: 01/09/2019] [Indexed: 01/12/2023]
|
10
|
Devang Divakar D, Alanazi SAS, Assiri MYA, Mohammed Halawani S, Zaid Alshehri S, Ahmed Saeed Al-Amri S, Mustafa M. Association between ENAM polymorphisms and dental caries in children. Saudi J Biol Sci 2018; 26:730-735. [PMID: 31048997 PMCID: PMC6486511 DOI: 10.1016/j.sjbs.2018.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 01/09/2018] [Accepted: 01/15/2018] [Indexed: 11/18/2022] Open
Abstract
Aim Dental enamel, the most rigid biological tissue of the tooth known to mankind, is the most integral and fundamental part of the tooth. Enamel matrixes compile 5% of Enamelin peptides and at the time of tooth development, they are considered to effect the formation and elongation of enamel crystallites. ENAM plays critical role in enamel formation. Any changes in ENAM may affect the thickness of enamel and may lead to dental caries. The present study is aimed to evaluate the association of ENAM gene polymorphisms and susceptibility of dental caries development risk. Material and methods The present study was carried out on 168 South Indian children, children’s with dental caries were included in study. Written consent was taken from their parents/guardians. Additionally 193 healthy individuals were enrolled as controls. Sampling was done after dental examination of the individuals. Three ENAM gene single nucleotide polymorphisms (SNPs) were rs7671281, rs3796704 and rs12640848 was genotyped to check their role in susceptibility of dental caries development risk. Results Out of three SNPs rs7671281 showed statistically significant risk association with dental caries susceptibility in this ethnic population at heterozygous allele CT (OR: 1.939, p = .01865) and with minor allele T (OR: 1.451, p = .001292). SNP rs3796704 showed significant protective association with dental caries in Indian population at heterozygous allele GA (OR: 0.409, p = .0192) and with minor allele A (OR: 0.645, p = .00875). SNP rs12640848 showed significant protective association with dental caries in Indian population at heterozygous allele AG (OR: 3.041, p = .00642) and with minor allele G (OR: 1.478, p = .02184). Preliminary insilico analysis also showed that rs7671281 (Ile648Thr) amino acid change will cause the structural and functional changes in ENAM protein. Conclusions In the present study significant association was observed between ENAM gene SNP rs7671281 and dental caries susceptibility in South Indian children. These results suggested that ENAM gene variants may contribute to dental caries in children.
Collapse
Affiliation(s)
- Darshan Devang Divakar
- Dental Biomaterials Research Chair, Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia
- Department of Oral Medicine and Radiology, KVG Dental College and Hospital, Sullia, Karnataka, India
- Corresponding author at: Dental Biomaterials Research Chair, Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia.
| | | | | | | | - Saleh Zaid Alshehri
- Department of Oral and Maxillofacial Surgery, College of Dentistry, King Saud University, Riyadh 11433, Saudi Arabia
| | - Saeed Ahmed Saeed Al-Amri
- Dental Public Health and Advanced Education in General Dentistry Resident, Department of Preventive Dentistry, Riyadh College for Dentistry and Pharmacy, Riyadh and Prince Sultan Dental Center (Namas General Hospital) MOH, Asser, Saudi Arabia
| | - Mohammed Mustafa
- Division of Endodontics, Department of Conservative Dental Sciences, College of Dentistry, Prince Sattam bin AbdulAziz University, P.O. Box:153, AlKharj 11942 Riyadh, Saudi Arabia
| |
Collapse
|
11
|
Neanderthal and Denisova tooth protein variants in present-day humans. PLoS One 2017; 12:e0183802. [PMID: 28902892 PMCID: PMC5597096 DOI: 10.1371/journal.pone.0183802] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 08/13/2017] [Indexed: 12/15/2022] Open
Abstract
Environment parameters, diet and genetic factors interact to shape tooth morphostructure. In the human lineage, archaic and modern hominins show differences in dental traits, including enamel thickness, but variability also exists among living populations. Several polymorphisms, in particular in the non-collagenous extracellular matrix proteins of the tooth hard tissues, like enamelin, are involved in dental structure variation and defects and may be associated with dental disorders or susceptibility to caries. To gain insights into the relationships between tooth protein polymorphisms and dental structural morphology and defects, we searched for non-synonymous polymorphisms in tooth proteins from Neanderthal and Denisova hominins. The objective was to identify archaic-specific missense variants that may explain the dental morphostructural variability between extinct and modern humans, and to explore their putative impact on present-day dental phenotypes. Thirteen non-collagenous extracellular matrix proteins specific to hard dental tissues have been selected, searched in the publicly available sequence databases of Neanderthal and Denisova individuals and compared with modern human genome data. A total of 16 non-synonymous polymorphisms were identified in 6 proteins (ameloblastin, amelotin, cementum protein 1, dentin matrix acidic phosphoprotein 1, enamelin and matrix Gla protein). Most of them are encoded by dentin and enamel genes located on chromosome 4, previously reported to show signs of archaic introgression within Africa. Among the variants shared with modern humans, two are ancestral (common with apes) and one is the derived enamelin major variant, T648I (rs7671281), associated with a thinner enamel and specific to the Homo lineage. All the others are specific to Neanderthals and Denisova, and are found at a very low frequency in modern Africans or East and South Asians, suggesting that they may be related to particular dental traits or disease susceptibility in these populations. This modern regional distribution of archaic dental polymorphisms may reflect persistence of archaic variants in some populations and may contribute in part to the geographic dental variations described in modern humans.
Collapse
|
12
|
Gasse B, Prasad M, Delgado S, Huckert M, Kawczynski M, Garret-Bernardin A, Lopez-Cazaux S, Bailleul-Forestier I, Manière MC, Stoetzel C, Bloch-Zupan A, Sire JY. Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta. Front Physiol 2017; 8:398. [PMID: 28659819 PMCID: PMC5469888 DOI: 10.3389/fphys.2017.00398] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/26/2017] [Indexed: 12/21/2022] Open
Abstract
Amelogenesis imperfecta (AI) designates a group of genetic diseases characterized by a large range of enamel disorders causing important social and health problems. These defects can result from mutations in enamel matrix proteins or protease encoding genes. A range of mutations in the enamel cleavage enzyme matrix metalloproteinase-20 gene (MMP20) produce enamel defects of varying severity. To address how various alterations produce a range of AI phenotypes, we performed a targeted analysis to find MMP20 mutations in French patients diagnosed with non-syndromic AI. Genomic DNA was isolated from saliva and MMP20 exons and exon-intron boundaries sequenced. We identified several homozygous or heterozygous mutations, putatively involved in the AI phenotypes. To validate missense mutations and predict sensitive positions in the MMP20 sequence, we evolutionarily compared 75 sequences extracted from the public databases using the Datamonkey webserver. These sequences were representative of mammalian lineages, covering more than 150 million years of evolution. This analysis allowed us to find 324 sensitive positions (out of the 483 MMP20 residues), pinpoint functionally important domains, and build an evolutionary chart of important conserved MMP20 regions. This is an efficient tool to identify new- and previously-identified mutations. We thus identified six functional MMP20 mutations in unrelated families, finding two novel mutated sites. The genotypes and phenotypes of these six mutations are described and compared. To date, 13 MMP20 mutations causing AI have been reported, making these genotypes and associated hypomature enamel phenotypes the most frequent in AI.
Collapse
Affiliation(s)
- Barbara Gasse
- Institut de Biologie Paris-Seine, UMR 7138-Evolution Paris-Seine, Sorbonne Universités, Université Pierre et Marie CurieParis, France
| | - Megana Prasad
- Laboratoire de Génétique Médicale, Institut National de la Santé et de la Recherche Médicale UMRS_1112, Institut de Génétique Médicale d'Alsace, FMTS, Université de StrasbourgStrasbourg, France
| | - Sidney Delgado
- Institut de Biologie Paris-Seine, UMR 7138-Evolution Paris-Seine, Sorbonne Universités, Université Pierre et Marie CurieParis, France
| | - Mathilde Huckert
- Laboratoire de Génétique Médicale, Institut National de la Santé et de la Recherche Médicale UMRS_1112, Institut de Génétique Médicale d'Alsace, FMTS, Université de StrasbourgStrasbourg, France.,Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France
| | - Marzena Kawczynski
- Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France.,Pôle de Médecine et Chirurgie Bucco-Dentaires, Centre de Référence des Manifestations Odontologiques des Maladies Rares, O-Rares, Hôpitaux Universitaires de StrasbourgStrasbourg, France
| | - Annelyse Garret-Bernardin
- Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France.,Unit of Dentistry, IRCCS, Bambino Gesù Children's HospitalRome, Italy
| | - Serena Lopez-Cazaux
- Faculté de Chirurgie Dentaire, Département d'Odontologie Pédiatrique, Centre de Compétences Maladies Rares, CHU Hôtel Dieu, Service d'odontologie Conservatrice et PédiatriqueNantes, France
| | - Isabelle Bailleul-Forestier
- Faculté de Chirurgie Dentaire, CHU de Toulouse, Centre de Compétences Maladies Rares, Odontologie Pédiatrique, Université Paul SabatierToulouse, France
| | - Marie-Cécile Manière
- Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France.,Pôle de Médecine et Chirurgie Bucco-Dentaires, Centre de Référence des Manifestations Odontologiques des Maladies Rares, O-Rares, Hôpitaux Universitaires de StrasbourgStrasbourg, France
| | - Corinne Stoetzel
- Laboratoire de Génétique Médicale, Institut National de la Santé et de la Recherche Médicale UMRS_1112, Institut de Génétique Médicale d'Alsace, FMTS, Université de StrasbourgStrasbourg, France
| | - Agnès Bloch-Zupan
- Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France.,Pôle de Médecine et Chirurgie Bucco-Dentaires, Centre de Référence des Manifestations Odontologiques des Maladies Rares, O-Rares, Hôpitaux Universitaires de StrasbourgStrasbourg, France.,Centre Européen de Recherche en Biologie et en Médecine, Centre National de la Recherche Scientifique UMR7104, Institut National de la Santé et de la Recherche Médicale U964, Institut de Génétique et de Biologie Moléculaire and Cellulaire, Université de StrasbourgIllkirch, France.,Institut d'Etudes Avancées, Université de Strasbourg, USIASStrasbourg, France.,Eastman Dental Institute, University College LondonLondon, United Kingdom
| | - Jean-Yves Sire
- Institut de Biologie Paris-Seine, UMR 7138-Evolution Paris-Seine, Sorbonne Universités, Université Pierre et Marie CurieParis, France
| |
Collapse
|
13
|
Evolutionary Analysis of the Mammalian Tuftelin Sequence Reveals Features of Functional Importance. J Mol Evol 2017; 84:214-224. [PMID: 28409196 DOI: 10.1007/s00239-017-9789-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 03/22/2017] [Indexed: 12/31/2022]
Abstract
Tuftelin (TUFT1) is an acidic, phosphorylated glycoprotein, initially discovered in developing enamel matrix. TUFT1 is expressed in many mineralized and non-mineralized tissues. We performed an evolutionary analysis of 82 mammalian TUFT1 sequences to identify residues and motifs that were conserved during 220 million years (Ma) of evolution. We showed that 168 residues (out of the 390 residues composing the human TUFT1 sequence) are under purifying selection. Our analyses identified several, new, putatively functional domains and confirmed previously described functional domains, such as the TIP39 interaction domain, which correlates with nuclear localization of the TUFT1 protein, that was demonstrated in several tissues. We also identified several sites under positive selection, which could indicate evolutionary changes possibly related to the functional diversification of TUFT1 during evolution in some lineages. We discovered that TUFT1 and MYZAP (myocardial zonula adherens protein) share a common ancestor that was duplicated circa 500 million years ago. Taken together, these findings expand our knowledge of TUFT1 evolution and provide new information that will be useful for further investigation of TUFT1 functions.
Collapse
|
14
|
Wang M, Qin M, Xia B. The association of Enamelin, Lactoferrin, and Tumour necrosis factor alpha gene polymorphisms with high caries susceptibility in Chinese children under 4 years old. Arch Oral Biol 2017; 80:75-81. [PMID: 28395167 DOI: 10.1016/j.archoralbio.2017.03.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 03/15/2017] [Accepted: 03/29/2017] [Indexed: 01/17/2023]
Abstract
OBJECTIVE The aim of this study was to assess the role of ENAM rs3796703, LTF rs1126478, and TNF-α rs1800629 in high caries susceptibility. DESIGN The present case-control study included 1005 unrelated children under 4 years old: 505 with severe caries (dmft index ≥4) and 500 who were caries-free (dmft index=0 and without white-spot lesions). Questionnaires were obtained from parents and gardians about the children's diet and oral behavioural habits. All the children received dental examinations and oral swabbing for human genomic DNA collection. ENAM rs3796703, LTF rs1126478, and TNF-α rs1800629 were genotyped by Sanger sequencing. RESULTS The frequency of the ENAM rs3796703T allele (6.7% in the caries group and 4.2% in the caries-free group), CT genotype (12.7% in the caries group and 8.4% in the caries-free group), TNF-α rs1800629 A allele (4.8% in the caries group and 6.8% in the caries-free group), and AG genotype (8.7% in the caries group and 13.2% in the caries-free group) were significantly different between the caries and caries-free groups (p<0.05). No significant difference was found in the LTF rs1126478 allele frequency and genotype distribution between the two groups. The ENAM rs3796703 CT genotype increased caries susceptibility by 60.9% compared to the CC genotype (β=0.746, OR=1.609), and the TNF-α rs1800629 AG genotype reduced caries susceptibility by 47.4% compared to the GG genotype (β=-0.642, OR=0.526). In terms of habits covariates, prolongation of night feeding time by 1 month increased caries susceptibility by 3.3% (β=0.033, OR=1.033); additionally, sweets and acidic drinks consumption 1-2 times per day increased caries susceptibility by 218.2% (β=1.158, OR=3.182), and consumption 3 or more times pe/r day increased susceptibility by 883.5% (β=2.286, OR=9.835) compared to non-consumption. Topical fluoride application decreased caries susceptibility by 43.0% (β=-0.562, OR=0.570). CONCLUSIONS The ENAM and TNF-α genes are likely associated with caries experience in Chinese children. The ENAM rs3796703 CT genotype might be involved in caries susceptibility, while TNF-α rs1800629 AG genotype might be involved in caries protection.
Collapse
Affiliation(s)
- Mengchen Wang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081, PR China.
| | - Man Qin
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081, PR China.
| | - Bin Xia
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081, PR China.
| |
Collapse
|
15
|
Daubert DM, Kelley JL, Udod YG, Habor C, Kleist CG, Furman IK, Tikonov IN, Swanson WJ, Roberts FA. Human enamel thickness and ENAM polymorphism. Int J Oral Sci 2016; 8:93-7. [PMID: 27357321 PMCID: PMC4932773 DOI: 10.1038/ijos.2016.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2015] [Indexed: 01/16/2023] Open
Abstract
The tooth enamel development gene, enamelin (ENAM), showed evidence of positive selection during a genome-wide scan of human and primate DNA for signs of adaptive evolution. The current study examined the hypothesis that a single-nucleotide polymorphism (SNP) C14625T (rs7671281) in the ENAM gene identified in the genome-wide scan is associated with a change in enamel phenotype. African Americans were selected as the target population, as they have been reported to have a target SNP frequency of approximately 50%, whereas non-Africans are predicted to have a 96% SNP frequency. Digital radiographs and DNA samples from 244 teeth in 133 subjects were analysed, and enamel thickness was assessed in relation to SNP status, controlling for age, sex, tooth number and crown length. Crown length was found to increase with molar number, and females were found to have thicker enamel. Teeth with larger crowns also had thicker enamel, and older subjects had thinner enamel. Linear regression and generalized estimating equations were used to investigate the relationship between enamel thickness of the mandibular molars and ENAM SNP status; enamel in subjects with the derived allele was significantly thinner (P=0.040) when the results were controlled for sex, age, tooth number and crown length. The derived allele demonstrated a recessive effect on the phenotype. The data indicate that thinner dental enamel is associated with the derived ENAM genotype. This is the first direct evidence of a dental gene implicated in human adaptive evolution as having a phenotypic effect on an oral structure.
Collapse
Affiliation(s)
- Diane M Daubert
- Department of Periodontics, University of Washington, Seattle, USA
| | - Joanna L Kelley
- Center for Reproductive Biology and School of Biological Sciences, Washington State University, Pullman, USA
| | - Yuriy G Udod
- Department of Periodontics, University of Washington, Seattle, USA
| | - Carolina Habor
- Department of Periodontics, University of Washington, Seattle, USA
| | - Chris G Kleist
- Department of Periodontics, University of Washington, Seattle, USA
| | - Ilona K Furman
- Department of Periodontics, University of Washington, Seattle, USA
| | - Igor N Tikonov
- Department of Periodontics, University of Washington, Seattle, USA
- Department of Oral and Maxillofacial Surgery, University of Texas Southwestern Medical Center, Dallas, USA
| | - Willie J Swanson
- Department of Genome Sciences, University of Washington, Seattle, USA
| | - Frank A Roberts
- Department of Periodontics, University of Washington, Seattle, USA
| |
Collapse
|
16
|
Evolutionary analysis of selective constraints identifies ameloblastin (AMBN) as a potential candidate for amelogenesis imperfecta. BMC Evol Biol 2015. [PMID: 26223266 PMCID: PMC4518657 DOI: 10.1186/s12862-015-0431-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Ameloblastin (AMBN) is a phosphorylated, proline/glutamine-rich protein secreted during enamel formation. Previous studies have revealed that this enamel matrix protein was present early in vertebrate evolution and certainly plays important roles during enamel formation although its precise functions remain unclear. We performed evolutionary analyses of AMBN in order to (i) identify residues and motifs important for the protein function, (ii) predict mutations responsible for genetic diseases, and (iii) understand its molecular evolution in mammals. Results In silico searches retrieved 56 complete sequences in public databases that were aligned and analyzed computationally. We showed that AMBN is globally evolving under moderate purifying selection in mammals and contains a strong phylogenetic signal. In addition, our analyses revealed codons evolving under significant positive selection. Evidence for positive selection acting on AMBN was observed in catarrhine primates and the aye-aye. We also found that (i) an additional translation initiation site was recruited in the ancestral placental AMBN, (ii) a short exon was duplicated several times in various species including catarrhine primates, and (iii) several polyadenylation sites are present. Conclusions AMBN possesses many positions, which have been subjected to strong selective pressure for 200 million years. These positions correspond to several cleavage sites and hydroxylated, O-glycosylated, and phosphorylated residues. We predict that these conserved positions would be potentially responsible for enamel disorder if substituted. Some motifs that were previously identified as potentially important functionally were confirmed, and we found two, highly conserved, new motifs, the function of which should be tested in the near future. This study illustrates the power of evolutionary analyses for characterizing the functional constraints acting on proteins with yet uncharacterized structure. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0431-0) contains supplementary material, which is available to authorized users.
Collapse
|
17
|
Springer MS, Signore AV, Paijmans JLA, Vélez-Juarbe J, Domning DP, Bauer CE, He K, Crerar L, Campos PF, Murphy WJ, Meredith RW, Gatesy J, Willerslev E, MacPhee RDE, Hofreiter M, Campbell KL. Interordinal gene capture, the phylogenetic position of Steller's sea cow based on molecular and morphological data, and the macroevolutionary history of Sirenia. Mol Phylogenet Evol 2015; 91:178-93. [PMID: 26050523 DOI: 10.1016/j.ympev.2015.05.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 05/22/2015] [Accepted: 05/28/2015] [Indexed: 01/02/2023]
Abstract
The recently extinct (ca. 1768) Steller's sea cow (Hydrodamalis gigas) was a large, edentulous North Pacific sirenian. The phylogenetic affinities of this taxon to other members of this clade, living and extinct, are uncertain based on previous morphological and molecular studies. We employed hybridization capture methods and second generation sequencing technology to obtain >30kb of exon sequences from 26 nuclear genes for both H. gigas and Dugong dugon. We also obtained complete coding sequences for the tooth-related enamelin (ENAM) gene. Hybridization probes designed using dugong and manatee sequences were both highly effective in retrieving sequences from H. gigas (mean=98.8% coverage), as were more divergent probes for regions of ENAM (99.0% coverage) that were designed exclusively from a proboscidean (African elephant) and a hyracoid (Cape hyrax). New sequences were combined with available sequences for representatives of all other afrotherian orders. We also expanded a previously published morphological matrix for living and fossil Sirenia by adding both new taxa and nine new postcranial characters. Maximum likelihood and parsimony analyses of the molecular data provide robust support for an association of H. gigas and D. dugon to the exclusion of living trichechids (manatees). Parsimony analyses of the morphological data also support the inclusion of H. gigas in Dugongidae with D. dugon and fossil dugongids. Timetree analyses based on calibration density approaches with hard- and soft-bounded constraints suggest that H. gigas and D. dugon diverged in the Oligocene and that crown sirenians last shared a common ancestor in the Eocene. The coding sequence for the ENAM gene in H. gigas does not contain frameshift mutations or stop codons, but there is a transversion mutation (AG to CG) in the acceptor splice site of intron 2. This disruption in the edentulous Steller's sea cow is consistent with previous studies that have documented inactivating mutations in tooth-specific loci of a variety of edentulous and enamelless vertebrates including birds, turtles, aardvarks, pangolins, xenarthrans, and baleen whales. Further, branch-site dN/dS analyses provide evidence for positive selection in ENAM on the stem dugongid branch where extensive tooth reduction occurred, followed by neutral evolution on the Hydrodamalis branch. Finally, we present a synthetic evolutionary tree for living and fossil sirenians showing several key innovations in the history of this clade including character state changes that parallel those that occurred in the evolutionary history of cetaceans.
Collapse
Affiliation(s)
- Mark S Springer
- Department of Biology, University of California, Riverside, CA 92521, USA.
| | - Anthony V Signore
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Johanna L A Paijmans
- Department of Biology, The University of York, Wentworth Way, Heslington, York YO10 5DD, UK
| | - Jorge Vélez-Juarbe
- Department of Mammalogy, Natural History Museum of Los Angeles County, Los Angeles, CA 90007, USA
| | - Daryl P Domning
- Laboratory of Evolutionary Biology, Department of Anatomy, Howard University, Washington, DC 20059, USA; Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA
| | - Cameron E Bauer
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Kai He
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Lorelei Crerar
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
| | - Paula F Campos
- Center for GeoGenetics, Natural History Museum, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark; CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal
| | - William J Murphy
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843, USA
| | - Robert W Meredith
- Department of Biology and Molecular Biology, Montclair State University, Montclair, NJ 07043, USA
| | - John Gatesy
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Eske Willerslev
- Center for GeoGenetics, Natural History Museum, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark
| | - Ross D E MacPhee
- Department of Mammalogy, American Museum of Natural History, New York, NY 10024, USA
| | - Michael Hofreiter
- Department of Biology, The University of York, Wentworth Way, Heslington, York YO10 5DD, UK; Adaptive and Evolutionary Genomics, Institute for Biochemistry and Biology, Faculty of Mathematics and Natural Sciences, University of Potsdam, Karl-Liebknecht-Strasse 24-24, 14476 Potsdam, Germany
| | - Kevin L Campbell
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
| |
Collapse
|
18
|
Kawasaki K, Amemiya CT. SCPP genes in the coelacanth: tissue mineralization genes shared by sarcopterygians. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2015; 322:390-402. [PMID: 25243252 DOI: 10.1002/jez.b.22546] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The coelacanth is the basal-most extant sarcopterygian that has teeth and tooth-like structures, comprising bone, dentin, and enamel or enameloid. Formation of these tissues involves many members of the secretory calcium-binding protein (SCPP) family. In tetrapods, acidic-residue-rich SCPPs are used in mineralization of bone and dentin, whereas Pro/Gln-rich SCPPs participate in enamel formation. Teleosts also employ many SCPPs for tissue mineralization. Nevertheless, the repertoire of SCPPs is largely different in teleosts and tetrapods; hence, filling this gap would be critical to elucidate early evolution of mineralized tissues in osteichthyans. In the present study, we searched for SCPP genes in the coelacanth genome and identified 11, of which two have clear orthologs in both tetrapods and teleosts, seven only in tetrapods, and two in neither of them. Given the divergence times of these vertebrate lineages, our discovery of this many SCPP genes shared between the coelacanth and tetrapods, but not with teleosts, suggests a complicated evolutionary scheme of SCPP genes in early osteichthyans. Our investigation also revealed both conserved and derived characteristics of SCPPs in the coelacanth and other vertebrates. Notably, acidic SCPPs independently evolved various acidic repeats in different lineages, while maintaining high acidity, presumably important for interactions with calcium. Furthermore, the three Pro/Gln-rich SCPP genes, required for mineralizing enamel matrix and confirmed only in tetrapods, were all identified in the coelacanth, strongly suggesting that enamel is equivalent in the coelacanth and tetrapods. This finding corroborates the previous proposition that true enamel evolved much earlier than the origin of tetrapods.
Collapse
|
19
|
Cui J, Xiao J, Tagliabracci VS, Wen J, Rahdar M, Dixon JE. A secretory kinase complex regulates extracellular protein phosphorylation. eLife 2015; 4:e06120. [PMID: 25789606 PMCID: PMC4421793 DOI: 10.7554/elife.06120] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/18/2015] [Indexed: 12/19/2022] Open
Abstract
Although numerous extracellular phosphoproteins have been identified, the protein kinases within the secretory pathway have only recently been discovered, and their regulation is virtually unexplored. Fam20C is the physiological Golgi casein kinase, which phosphorylates many secreted proteins and is critical for proper biomineralization. Fam20A, a Fam20C paralog, is essential for enamel formation, but the biochemical function of Fam20A is unknown. Here we show that Fam20A potentiates Fam20C kinase activity and promotes the phosphorylation of enamel matrix proteins in vitro and in cells. Mechanistically, Fam20A is a pseudokinase that forms a functional complex with Fam20C, and this complex enhances extracellular protein phosphorylation within the secretory pathway. Our findings shed light on the molecular mechanism by which Fam20C and Fam20A collaborate to control enamel formation, and provide the first insight into the regulation of secretory pathway phosphorylation. DOI:http://dx.doi.org/10.7554/eLife.06120.001 Some proteins must be modified in order to work effectively. One common modification is to add a phosphate group to the protein, which is performed by enzymes called protein kinases. Although most of the protein kinases work on proteins inside the cell, it was discovered recently that a small group of kinases work within the ‘secretory pathway’ and modify proteins that are released (or secreted) out of cells. One such secretory pathway kinase—called Fam20C—phosphorylates a wide range of secreted proteins and helps to ensure the proper development of bones and teeth. Specifically, Fam20C and a closely related protein called Fam20A are important for forming enamel, the hardest substance in human body, which makes up the outer surface of teeth. However, the exact role of Fam20A is unknown. Cui et al. now show that Fam20A binds to Fam20C, and this increases the ability of Fam20C to phosphorylate the proteins that form the ‘matrix’ that guides the deposition of the enamel minerals. Furthermore, mutations in Fam20A lead to the inefficient phosphorylation of enamel matrix proteins by Fam20C, and prevent proper enamel formation. The results raise the possibility that similar mechanisms of secretory kinase activation may also be important in other biological processes where many secreted proteins need to be phosphorylated rapidly. DOI:http://dx.doi.org/10.7554/eLife.06120.002
Collapse
Affiliation(s)
- Jixin Cui
- Department of Pharmacology, University of California, San Diego, La Jolla, United States
| | - Junyu Xiao
- Department of Pharmacology, University of California, San Diego, La Jolla, United States
| | - Vincent S Tagliabracci
- Department of Pharmacology, University of California, San Diego, La Jolla, United States
| | - Jianzhong Wen
- Department of Pharmacology, University of California, San Diego, La Jolla, United States
| | - Meghdad Rahdar
- Department of Pharmacology, University of California, San Diego, La Jolla, United States
| | - Jack E Dixon
- Department of Pharmacology, University of California, San Diego, La Jolla, United States
| |
Collapse
|
20
|
Gasse B, Chiari Y, Silvent J, Davit-Béal T, Sire JY. Amelotin: an enamel matrix protein that experienced distinct evolutionary histories in amphibians, sauropsids and mammals. BMC Evol Biol 2015; 15:47. [PMID: 25884299 PMCID: PMC4373244 DOI: 10.1186/s12862-015-0329-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 02/24/2015] [Indexed: 01/21/2023] Open
Abstract
Background Amelotin (AMTN) is an ameloblast-secreted protein that belongs to the secretory calcium-binding phosphoprotein (SCPP) family, which originated in early vertebrates. In rodents, AMTN is expressed during the maturation stage of amelogenesis only. This expression pattern strongly differs from the spatiotemporal expression of other ameloblast-secreted SCPPs, such as the enamel matrix proteins (EMPs). Furthermore, AMTN was characterized in rodents only. In this study, we applied various approaches, including in silico screening of databases, PCRs and transcriptome sequencing to characterize AMTN sequences in sauropsids and amphibians, and compared them to available mammalian and coelacanth sequences. Results We showed that (i) AMTN is tooth (enamel) specific and underwent pseudogenization in toothless turtles and birds, and (ii) the AMTN structure changed during tetrapod evolution. To infer AMTN function, we studied spatiotemporal expression of AMTN during amelogenesis in a salamander and a lizard, and compared the results with available expression data from mouse. We found that AMTN is expressed throughout amelogenesis in non-mammalian tetrapods, in contrast to its expression limited to enamel maturation in rodents. Conclusions Taken together our findings suggest that AMTN was primarily an EMP. Its functions were conserved in amphibians and sauropsids while a change occurred early in the mammalian lineage, modifying its expression pattern during amelogenesis and its gene structure. These changes likely led to a partial loss of AMTN function and could have a link with the emergence of prismatic enamel in mammals. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0329-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Barbara Gasse
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Evolution Paris-Seine, Paris, UMR7138, France.
| | - Ylenia Chiari
- Department of Biology, University of South Alabama, Mobile, AL, 36688, USA.
| | - Jérémie Silvent
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Evolution Paris-Seine, Paris, UMR7138, France. .,Department of Structural Biology, Weizmann Institute of Science, Rehovot, 76100, Israel.
| | - Tiphaine Davit-Béal
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Evolution Paris-Seine, Paris, UMR7138, France.
| | - Jean-Yves Sire
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Evolution Paris-Seine, Paris, UMR7138, France.
| |
Collapse
|
21
|
Meredith RW, Zhang G, Gilbert MTP, Jarvis ED, Springer MS. Evidence for a single loss of mineralized teeth in the common avian ancestor. Science 2014; 346:1254390. [DOI: 10.1126/science.1254390] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
22
|
Silvent J, Gasse B, Mornet E, Sire JY. Molecular evolution of the tissue-nonspecific alkaline phosphatase allows prediction and validation of missense mutations responsible for hypophosphatasia. J Biol Chem 2014; 289:24168-79. [PMID: 25023282 DOI: 10.1074/jbc.m114.576843] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
ALPL encodes the tissue nonspecific alkaline phosphatase (TNSALP), which removes phosphate groups from various substrates. Its function is essential for bone and tooth mineralization. In humans, ALPL mutations lead to hypophosphatasia, a genetic disorder characterized by defective bone and/or tooth mineralization. To date, 275 ALPL mutations have been reported to cause hypophosphatasia, of which 204 were simple missense mutations. Molecular evolutionary analysis has proved to be an efficient method to highlight residues important for the protein function and to predict or validate sensitive positions for genetic disease. Here we analyzed 58 mammalian TNSALP to identify amino acids unchanged, or only substituted by residues sharing similar properties, through 220 millions years of mammalian evolution. We found 469 sensitive positions of the 524 residues of human TNSALP, which indicates a highly constrained protein. Any substitution occurring at one of these positions is predicted to lead to hypophosphatasia. We tested the 204 missense mutations resulting in hypophosphatasia against our predictive chart, and validated 99% of them. Most sensitive positions were located in functionally important regions of TNSALP (active site, homodimeric interface, crown domain, calcium site, …). However, some important positions are located in regions, the structure and/or biological function of which are still unknown. Our chart of sensitive positions in human TNSALP (i) enables to validate or invalidate at low cost any ALPL mutation, which would be suspected to be responsible for hypophosphatasia, by contrast with time consuming and expensive functional tests, and (ii) displays higher predictive power than in silico models of prediction.
Collapse
Affiliation(s)
- Jérémie Silvent
- From the Université Pierre & Marie Curie, IBPS, Evolution Paris Seine, 7 quai St-Bernard, Case 05, 75005 Paris and
| | - Barbara Gasse
- From the Université Pierre & Marie Curie, IBPS, Evolution Paris Seine, 7 quai St-Bernard, Case 05, 75005 Paris and
| | - Etienne Mornet
- the Unité de Pathologie Cellulaire et Génétique, EA2493, Université de Versailles-Saint Quentin en Yvelines, Versailles & Unité de Génétique Constitutionnelle, Centre Hospitalier de Versailles, 78150 Le Chesnay, France
| | - Jean-Yves Sire
- From the Université Pierre & Marie Curie, IBPS, Evolution Paris Seine, 7 quai St-Bernard, Case 05, 75005 Paris and
| |
Collapse
|
23
|
Horvath JE, Ramachandran GL, Fedrigo O, Nielsen WJ, Babbitt CC, St Clair EM, Pfefferle LW, Jernvall J, Wray GA, Wall CE. Genetic comparisons yield insight into the evolution of enamel thickness during human evolution. J Hum Evol 2014; 73:75-87. [PMID: 24810709 DOI: 10.1016/j.jhevol.2014.01.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 10/29/2013] [Accepted: 01/09/2014] [Indexed: 12/29/2022]
Abstract
Enamel thickness varies substantially among extant hominoids and is a key trait with significance for interpreting dietary adaptation, life history trajectory, and phylogenetic relationships. There is a strong link in humans between enamel formation and mutations in the exons of the four genes that code for the enamel matrix proteins and the associated protease. The evolution of thick enamel in humans may have included changes in the regulation of these genes during tooth development. The cis-regulatory region in the 5' flank (upstream non-coding region) of MMP20, which codes for enamelysin, the predominant protease active during enamel secretion, has previously been shown to be under strong positive selection in the lineages leading to both humans and chimpanzees. Here we examine evidence for positive selection in the 5' flank and 3' flank of AMELX, AMBN, ENAM, and MMP20. We contrast the human sequence changes with other hominoids (chimpanzees, gorillas, orangutans, gibbons) and rhesus macaques (outgroup), a sample comprising a range of enamel thickness. We find no evidence for positive selection in the protein-coding regions of any of these genes. In contrast, we find strong evidence for positive selection in the 5' flank region of MMP20 and ENAM along the lineage leading to humans, and in both the 5' flank and 3' flank regions of MMP20 along the lineage leading to chimpanzees. We also identify putative transcription factor binding sites overlapping some of the species-specific nucleotide sites and we refine which sections of the up- and downstream putative regulatory regions are most likely to harbor important changes. These non-coding changes and their potential for differential regulation by transcription factors known to regulate tooth development may offer insight into the mechanisms that allow for rapid evolutionary changes in enamel thickness across closely-related species, and contribute to our understanding of the enamel phenotype in hominoids.
Collapse
Affiliation(s)
- Julie E Horvath
- North Carolina Museum of Natural Sciences, Nature Research Center, Raleigh, NC 27601, USA; Department of Biology, North Carolina Central University, Durham, NC 27707, USA; Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA; Duke Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA
| | | | - Olivier Fedrigo
- Duke Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA
| | | | - Courtney C Babbitt
- Duke Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA; Department of Biology, Duke University, Durham, NC 27708, USA
| | | | | | - Jukka Jernvall
- Institute for Biotechnology, University of Helsinki, Helsinki, Finland
| | - Gregory A Wray
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA; Duke Institute for Genome Sciences and Policy, Duke University, Durham, NC 27708, USA; Department of Biology, Duke University, Durham, NC 27708, USA
| | - Christine E Wall
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.
| |
Collapse
|
24
|
Chaussain C, Bouazza N, Gasse B, Laffont AG, Opsahl Vital S, Davit-Béal T, Moulis E, Chabadel O, Hennequin M, Courson F, Droz D, Vaysse F, Laboux O, Tassery H, Carel JC, Alcais A, Treluyer JM, Beldjord C, Sire JY. Dental caries and enamelin haplotype. J Dent Res 2014; 93:360-5. [PMID: 24487377 DOI: 10.1177/0022034514522060] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In the literature, the enamelin gene ENAM has been repeatedly designated as a possible candidate for caries susceptibility. Here, we checked whether ENAM variants could increase caries susceptibility. To this aim, we sequenced coding exons and exon-intron boundaries of ENAM in 250 children with a severe caries phenotype and in 149 caries-free patients from 9 French hospital groups. In total, 23 single-nucleotide polymorphisms (SNPs) were found, but none appeared to be responsible for a direct change of ENAM function. Six SNPs had a high minor allele frequency (MAF) and 6 others were identified for the first time. Statistical and evolutionary analyses showed that none of these SNPs was associated with caries susceptibility or caries protection when studied separately and challenged with environmental factors. However, haplotype interaction analysis showed that the presence, in a same variant, of 2 exonic SNPs (rs7671281 and rs3796704; MAF 0.12 and 0.10, respectively), both changing an amino acid in the protein region encoded by exon 10 (p.I648T and p.R763Q, respectively), increased caries susceptibility 2.66-fold independent of the environmental risk factors. These findings support ENAM as a gene candidate for caries susceptibility in the studied population.
Collapse
Affiliation(s)
- C Chaussain
- AP-HP, Service Odontologie Bretonneau - Louis Mourier HUPNVS and Centre de référence des maladies du métabolisme du phosphore et du calcium, Paris, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Wang SK, Samann AC, Hu JCC, Simmer JP. FAM20C functions intracellularly within both ameloblasts and odontoblasts in vivo. J Bone Miner Res 2013; 28:2508-11. [PMID: 23703840 PMCID: PMC3836880 DOI: 10.1002/jbmr.1990] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 05/07/2013] [Accepted: 05/10/2013] [Indexed: 12/21/2022]
Abstract
FAM20C, also known as Golgi casein kinase (G-CK), is proposed to be the archetype for a family of secreted kinases that phosphorylate target proteins in the Golgi and in extracellular matrices, but FAM20C serving an extracellular function is controversial. FAM20C phosphorylates secretory calcium-binding phosphoproteins (SCPPs), which are associated with the evolution of biomineralization in vertebrates. Current models of biomineralization assume SCPP proteins are secreted as phosphoproteins and their phosphates are essential for protein conformation and function. It would be a radical departure from current theories if proteins in mineralizing matrices were dephosphorylated as part of the mineralization mechanism and rephosphorylated in the extracellular milieu by FAM20C using ATP. To see if such mechanisms are possible in the formation of dental enamel, we tested the hypothesis that FAM20C is secreted by ameloblasts and accumulates in the enamel extracellular matrix during tooth development. FAM20C localization was determined by immunohistochemistry in day 5 mouse incisors and molars and by Western blot analyses of proteins extracted from pig enamel organ epithelia (EOE) and enamel shavings. FAM20C localized intracellularly within ameloblasts and odontoblasts in a pattern consistent with Golgi localization. Western blots detected FAM20C in the EOE extracts but not in the enamel matrix. We conclude that FAM20C is not a constituent of the enamel extracellular matrix and functions intracellularly within ameloblasts.
Collapse
Affiliation(s)
- Shih-Kai Wang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, 48108 USA
| | - Andrew C. Samann
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, 48108 USA
| | - Jan C-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, 48108 USA
| | - James P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, 48108 USA
| |
Collapse
|
26
|
Bartlett JD. Dental enamel development: proteinases and their enamel matrix substrates. ISRN DENTISTRY 2013; 2013:684607. [PMID: 24159389 PMCID: PMC3789414 DOI: 10.1155/2013/684607] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 07/15/2013] [Indexed: 12/31/2022]
Abstract
This review focuses on recent discoveries and delves in detail about what is known about each of the proteins (amelogenin, ameloblastin, and enamelin) and proteinases (matrix metalloproteinase-20 and kallikrein-related peptidase-4) that are secreted into the enamel matrix. After an overview of enamel development, this review focuses on these enamel proteins by describing their nomenclature, tissue expression, functions, proteinase activation, and proteinase substrate specificity. These proteins and their respective null mice and human mutations are also evaluated to shed light on the mechanisms that cause nonsyndromic enamel malformations termed amelogenesis imperfecta. Pertinent controversies are addressed. For example, do any of these proteins have a critical function in addition to their role in enamel development? Does amelogenin initiate crystallite growth, does it inhibit crystallite growth in width and thickness, or does it do neither? Detailed examination of the null mouse literature provides unmistakable clues and/or answers to these questions, and this data is thoroughly analyzed. Striking conclusions from this analysis reveal that widely held paradigms of enamel formation are inadequate. The final section of this review weaves the recent data into a plausible new mechanism by which these enamel matrix proteins support and promote enamel development.
Collapse
Affiliation(s)
- John D. Bartlett
- Harvard School of Dental Medicine & Chair, Department of Mineralized Tissue Biology, The Forsyth Institute, 245 First Street, Cambridge MA 02142, USA
| |
Collapse
|
27
|
Gallon V, Chen L, Yang X, Moradian-Oldak J. Localization and quantitative co-localization of enamelin with amelogenin. J Struct Biol 2013; 183:239-49. [PMID: 23563189 PMCID: PMC3737400 DOI: 10.1016/j.jsb.2013.03.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 03/11/2013] [Accepted: 03/25/2013] [Indexed: 02/07/2023]
Abstract
Enamelin and amelogenin are vital proteins in enamel formation. The cooperative function of these two proteins controls crystal nucleation and morphology in vitro. We quantitatively analyzed the co-localization between enamelin and amelogenin by confocal microscopy and using two antibodies, one raised against a sequence in the porcine 32 kDa enamelin region and the other raised against full-length recombinant mouse amelogenin. We further investigated the interaction of the porcine 32 kDa enamelin and recombinant amelogenin using immuno-gold labeling. This study reports the quantitative co-localization results for postnatal days 1-8 mandibular mouse molars. We show that amelogenin and enamelin are secreted into the extracellular matrix on the cuspal slopes of the molars at day 1 and that secretion continues to at least day 8. Quantitative co-localization analysis (QCA) was performed in several different configurations using large (45 μm height, 33 μm width) and small (7 μm diameter) regions of interest to elucidate any patterns. Co-localization patterns in day 8 samples revealed that enamelin and amelogenin co-localize near the secretory face of the ameloblasts and appear to be secreted approximately in a 1:1 ratio. The degree of co-localization decreases as the enamel matures, both along the secretory face of ameloblasts and throughout the entire thickness of the enamel. Immuno-reactivity against enamelin is concentrated along the secretory face of ameloblasts, supporting the theory that this protein together with amelogenin is intimately involved in mineral induction at the beginning of enamel formation.
Collapse
Affiliation(s)
- Victoria Gallon
- Center for Craniofacial Molecular Biology, University of Southern California, Herman Ostrow School of Dentistry, Los Angeles, CA 90033, USA
| | | | | | | |
Collapse
|
28
|
Gasse B, Karayigit E, Mathieu E, Jung S, Garret A, Huckert M, Morkmued S, Schneider C, Vidal L, Hemmerlé J, Sire JY, Bloch-Zupan A. Homozygous and compound heterozygous MMP20 mutations in amelogenesis imperfecta. J Dent Res 2013; 92:598-603. [PMID: 23625376 DOI: 10.1177/0022034513488393] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In this article, we focus on hypomaturation autosomal-recessive-type amelogenesis imperfecta (type IIA2) and describe 2 new causal Matrix metalloproteinase 20 (MMP20) mutations validated in two unrelated families: a missense mutation p.T130I at the expected homozygous state, and a compound heterozygous mutation having the same mutation combined with a nucleotide deletion, leading to a premature stop codon (p.N120fz*2). We characterized the enamel structure of the latter case using scanning electron microscopy analysis and microanalysis (Energy-dispersive X-ray Spectroscopy, EDX) and confirmed the hypomaturation-type amelogenesis imperfecta as identified in the clinical diagnosis. The mineralized content was slightly decreased, with magnesium substituting for calcium in the crystal structure. The anomalies affected enamel with minimal inter-rod enamel present and apatite crystals perpendicular to the enamel prisms, suggesting a possible new role for MMP20 in enamel formation.
Collapse
Affiliation(s)
- B Gasse
- Research group Evolution & Développement du Squelette-EDS, UMR 7138-SAE, Université Pierre et Marie Curie, Paris, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Silvent J, Sire JY, Delgado S. The dentin matrix acidic phosphoprotein 1 (DMP1) in the light of mammalian evolution. J Mol Evol 2013; 76:59-70. [PMID: 23361408 DOI: 10.1007/s00239-013-9539-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 01/06/2013] [Indexed: 12/17/2022]
Abstract
Dentin matrix acidic phosphoprotein 1 (DMP1) is an acidic, highly phosphorylated, noncollagenous protein secreted during dentin and bone formation. Previous functional studies of DMP1 have revealed various motifs playing a role in either mineralization or cell differentiation. We performed an evolutionary analysis of DMP1 to identify residues and motifs that were conserved during 220 millions years (Ma) of mammalian evolution, and hence have an important function. In silico search provided us with 41 sequences that were aligned and analyzed using the Hyphy program. We showed that DMP1 contains 55 positions that were kept unchanged for 220 Ma. We also defined in a more precise manner some motifs that were already known (i.e., cleavage sites, RGD motif, ASARM peptide, glycosaminoglycan chain attachment site, nuclear localization signal sites, and dentin sialophosphoprotein-binding site), and we found five, highly conserved, new functional motifs. In the near future, functional studies could be performed to understand the role played by them.
Collapse
|
30
|
Meredith RW, Gatesy J, Springer MS. Molecular decay of enamel matrix protein genes in turtles and other edentulous amniotes. BMC Evol Biol 2013; 13:20. [PMID: 23342979 PMCID: PMC3562159 DOI: 10.1186/1471-2148-13-20] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 01/16/2013] [Indexed: 11/20/2022] Open
Abstract
Background Secondary edentulism (toothlessness) has evolved on multiple occasions in amniotes including several mammalian lineages (pangolins, anteaters, baleen whales), birds, and turtles. All edentulous amniote clades have evolved from ancestors with enamel-capped teeth. Previous studies have documented the molecular decay of tooth-specific genes in edentulous mammals, all of which lost their teeth in the Cenozoic, and birds, which lost their teeth in the Cretaceous. By contrast with mammals and birds, tooth loss in turtles occurred in the Jurassic (201.6-145.5 Ma), providing an extended time window for tooth gene degradation in this clade. The release of the painted turtle and Chinese softshell turtle genomes provides an opportunity to recover the decayed remains of tooth-specific genes in Testudines. Results We queried available genomes of Testudines (Chrysemys picta [painted turtle], Pelodiscus sinensis [Chinese softshell turtle]), Aves (Anas platyrhynchos [duck], Gallus gallus [chicken], Meleagris gallopavo [turkey], Melopsittacus undulatus [budgerigar], Taeniopygia guttata [zebra finch]), and enamelless mammals (Orycteropus afer [aardvark], Choloepus hoffmanni [Hoffmann’s two-toed sloth], Dasypus novemcinctus [nine-banded armadillo]) for remnants of three enamel matrix protein (EMP) genes with putative enamel-specific functions. Remnants of the AMBN and ENAM genes were recovered in Chrysemys and retain their original synteny. Remnants of AMEL were recovered in both testudines, although there are no shared frameshifts. We also show that there are inactivated copies of AMBN, AMEL and ENAM in representatives of divergent avian lineages including Galloanserae, Passeriformes, and Psittaciformes, and that there are shared frameshift mutations in all three genes that predate the basal split in Neognathae. Among enamelless mammals, all three EMP genes exhibit inactivating mutations in Orycteropus and Choloepus. Conclusions Our results highlight the power of combining fossil and genomic evidence to decipher macroevolutionary transitions and characterize the functional range of different loci involved in tooth development. The fossil record and phylogenetics combine to predict the occurrence of molecular fossils of tooth-specific genes in the genomes of edentulous amniotes, and in every case these molecular fossils have been discovered. The widespread occurrence of EMP pseudogenes in turtles, birds, and edentulous/enamelless mammals also provides compelling evidence that in amniotes, the only unique, non-redundant function of these genes is in enamel formation.
Collapse
Affiliation(s)
- Robert W Meredith
- Department of Biology, University of California, Riverside, CA 92521, USA
| | | | | |
Collapse
|
31
|
Gasse B, Silvent J, Sire JY. Evolutionary analysis suggests that AMTN is enamel-specific and a candidate for AI. J Dent Res 2012; 91:1085-9. [PMID: 22968158 DOI: 10.1177/0022034512460551] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Molecular evolutionary analysis is an efficient method to predict and/or validate amino acid substitutions that could lead to a genetic disease and to highlight residues and motifs that could play an important role in the protein structure and/or function. We have applied such analysis to amelotin (AMTN), a recently identified enamel protein in the rat, mouse, and humans. An in silico search for AMTN provided 42 new mammalian sequences that were added to the 3 published sequences with which we performed the analysis using a dataset representative of all lineages (circa 220 million years of evolution), including 2 enamel-less species, sloth and armadillo. During evolution, of the 209 residues of human AMTN, 17 were unchanged and 34 had conserved their chemical properties. Substituting these important residues could lead to amelogenesis imperfecta (AI). Also, AMTN possesses a well-conserved signal peptide, 2 conserved motifs whose function is certainly important but unknown, and a putative phosphorylation site (SXE). In addition, the sequences of the 2 enamel-less species display mutations revealing that AMTN underwent pseudogenization, which suggests that AMTN is an enamel-specific protein.
Collapse
Affiliation(s)
- B Gasse
- Université Pierre et Marie Curie, UMR 7138, EDS research group, 7 quai St-Bernard, Case 5, 75005 Paris, France
| | | | | |
Collapse
|
32
|
Abstract
Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable mechanical properties of enamel are associated with its hierarchical structural organization and its thorough connection with underlying dentin. This dynamic mineralizing system offers scientists a wealth of information that allows the study of basic principels of organic matrix-mediated biomineralization and can potentially be utilized in the fields of material science and engineering for development and design of biomimetic materials. This chapter will provide a brief overview of enamel hierarchical structure and properties and the process and stages of amelogenesis. Particular emphasis is given to current knowledge of extracellular matrix protein and proteinases, and the structural chemistry of the matrix components and their putative functions. The chapter will conclude by discussing the potential of enamel for regrowth.
Collapse
Affiliation(s)
- Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA.
| |
Collapse
|
33
|
Brookes SJ, Kingswell NJ, Barron MJ, Dixon MJ, Kirkham J. Is the 32-kDa fragment the functional enamelin unit in all species? Eur J Oral Sci 2011; 119 Suppl 1:345-50. [PMID: 22243266 PMCID: PMC3427898 DOI: 10.1111/j.1600-0722.2011.00869.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Enamelin is an extracellular enamel matrix protein essential for normal amelogenesis. After secretion, porcine enamelin is processed to generate several enamelin-degradation products. The cumulative 32-kDa enamelin is the most abundant enamelin present, and various roles for this molecule have been suggested. However, the proteolytic cleavage sites in porcine enamelin that generate the 32-kDa enamelin are not conserved across species, and the 32-kDa enamelin analogue may not be present in all species. To explore this we studied rat enamelin biochemistry using western blotting with anti-peptide IgGs to porcine 32-kDa enamelin and to the putative rat 32-kDa enamelin analogue. The dominant enamelins in secretory-stage rat enamel migrated at around 60-70 kDa. In contrast, the dominant enamelins in secretory-stage porcine enamel migrated at around 32 kDa. In contrast, secretory-stage porcine-enamel enamelins were dominated by the 32-kDa enamelin. Rat enamelin was completely removed from maturation-stage enamel without any accumulation of 32-kDa enamelin. We suggest that a discrete 32-kDa enamelin is not essential for normal amelogenesis in all species, and in pig it may be a processing product of a larger functional enamelin molecule. The pig may be an atypical model in terms of enamelin biochemistry and function, and caution should be exercised when assigning functional roles to the 32-kDa enamelin as a discrete enamel matrix entity.
Collapse
Affiliation(s)
- Steven J Brookes
- Department of Oral Biology, Leeds Dental Institute, University of Leeds, Leeds, UK.
| | | | | | | | | |
Collapse
|
34
|
Abstract
The structures and interactions among macromolecules in the enamel extracellular matrix play vital roles in regulating hydroxyapatite crystal nucleation, growth, and maturation. We used dynamic light scattering (DLS), circular dichroism (CD), fluorescence spectroscopy, and transmission electron microscopy (TEM) to investigate the association of amelogenin and the 32-kDa enamelin, at physiological pH 7.4, in phosphate-buffered saline (PBS). The self-assembly behavior of amelogenin (rP148) was altered following addition of the 32-kDa enamelin. Dynamic light scattering revealed a trend for a decrease in aggregate size in the solution following the addition of enamelin to amelogenin. A blue-shift and intensity increase of the ellipticity minima of rP148 in the CD spectra upon the addition of the 32-kDa enamelin, suggest a direct interaction between the two proteins. In the fluorescence spectra, the maximum emission of rP148 was red-shifted from 335 to 341 nm with a marked intensity increase in the presence of enamelin as a result of complexation of the two proteins. In agreement with DLS data, TEM imaging showed that the 32-kDa enamelin dispersed the amelogenin aggregates into oligomeric particles and stabilized them. Our study provides novel insights into understanding the possible cooperation between enamelin and amelogenin in macromolecular co-assembly and in controlling enamel mineral formation.
Collapse
Affiliation(s)
- Xiudong Yang
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
| | | | | | | |
Collapse
|
35
|
Yamakoshi Y, Yamakoshi F, Hu JCC, Simmer JP. Characterization of kallikrein-related peptidase 4 glycosylations. Eur J Oral Sci 2011; 119 Suppl 1:234-40. [PMID: 22243251 PMCID: PMC3282036 DOI: 10.1111/j.1600-0722.2011.00863.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Kallikrein-related peptidase 4 (KLK4) is a glycosylated serine protease that functions in the maturation (hardening) of dental enamel. Pig and mouse KLK4 contain three potential N-glycosylation sites. We isolated KLK4 from developing pig and mouse molars and characterized their N-glycosylations. N-glycans were enzymatically released by digestion with N-glycosidase F and fluorescently labeled with 2-aminobenzoic acid. Normal-phase high-performance liquid chromatography (NP-HPLC) revealed N-glycans with no, or with one, two, or three sialic acid attachments in pig KLK4 and with no, or with one or two sialic acid attachments in mouse KLK4. The labeled N-glycans were digested with sialidase to generate the asialo N-glycan cores that were fractionated by reverse-phase HPLC, and their retention times were compared with similarly labeled glycan standards. The purified cores were characterized by mass spectrometric and monosaccharide composition analyses. We determined that pig and mouse KLK4 have NA2 and NA2F biantennary N-glycan cores. The pig triantennary core is NA3. The mouse triantennary core is NA3 with a fucose connected by an α1-6 linkage, indicating that it is attached to the first N-acetyglucosamine (NA3F). We conclude that pig KLK4 has NA2, NA2F, and NA3 N-glycan cores with no, or with one, two, or three sialic acids. Mouse KLK4 has NA2, NA2F, and NA3F N-glycan cores with no, or with one or two sialic acids.
Collapse
Affiliation(s)
- Yasuo Yamakoshi
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Eisenhower Place, Ann Arbor, MI 48108, USA
| | | | | | | |
Collapse
|
36
|
Meredith RW, Gatesy J, Cheng J, Springer MS. Pseudogenization of the tooth gene enamelysin (MMP20) in the common ancestor of extant baleen whales. Proc Biol Sci 2011; 278:993-1002. [PMID: 20861053 PMCID: PMC3049022 DOI: 10.1098/rspb.2010.1280] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 08/31/2010] [Indexed: 01/11/2023] Open
Abstract
Whales in the suborder Mysticeti are filter feeders that use baleen to sift zooplankton and small fish from ocean waters. Adult mysticetes lack teeth, although tooth buds are present in foetal stages. Cladistic analyses suggest that functional teeth were lost in the common ancestor of crown-group Mysticeti. DNA sequences for the tooth-specific genes, ameloblastin (AMBN), enamelin (ENAM) and amelogenin (AMEL), have frameshift mutations and/or stop codons in this taxon, but none of these molecular cavities are shared by all extant mysticetes. Here, we provide the first evidence for pseudogenization of a tooth gene, enamelysin (MMP20), in the common ancestor of living baleen whales. Specifically, pseudogenization resulted from the insertion of a CHR-2 SINE retroposon in exon 2 of MMP20. Genomic and palaeontological data now provide congruent support for the loss of enamel-capped teeth on the common ancestral branch of crown-group mysticetes. The new data for MMP20 also document a polymorphic stop codon in exon 2 of the pygmy sperm whale (Kogia breviceps), which has enamel-less teeth. These results, in conjunction with the evidence for pseudogenization of MMP20 in Hoffmann's two-toed sloth (Choloepus hoffmanni), another enamel-less species, support the hypothesis that the only unique, non-overlapping function of the MMP20 gene is in enamel formation.
Collapse
Affiliation(s)
| | | | | | - Mark S. Springer
- Department of Biology, University of California, Riverside, CA 92521, USA
| |
Collapse
|
37
|
Berland S, Marie A, Duplat D, Milet C, Sire JY, Bédouet L. Coupling proteomics and transcriptomics for the identification of novel and variant forms of mollusk shell proteins: a study with P. margaritifera. Chembiochem 2011; 12:950-61. [PMID: 21404418 DOI: 10.1002/cbic.201000667] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Indexed: 01/22/2023]
Abstract
Shell matrix proteins from Pinctada margaritifera were characterized by combining proteomics analysis of shell organic extracts and transcript sequences, both obtained from the shell-forming cell by using the suppression subtractive hybridization method (SSH) and from an expressed sequence tag (EST) database available from Pinctada maxima mantle tissue. Some of the identified proteins were homologues to proteins reported in other mollusk shells, namely lysine-rich matrix proteins (KRMPs), shematrins and molluscan prismatic and nacreous layer 88 kDa (MPN88). Sequence comparison within and among Pinctada species pointed to intra- and interspecies variations relevant to polymorphism and to evolutionary distance, respectively. In addition, a novel shell matrix protein, linkine was identified. BLAST analysis of the peptide sequences obtained from the shell of P. margaritifera against the EST database revealed the presence of additional proteins: two proteins similar to the Pif97 protein that was identified in the shell of P. fucata, a chitinase-like protein previously identified in Crassostrea gigas, two chitin-binding proteins, and two incomplete sequences of proteins unknown so far in mollusk shells. Combining proteomics and transcriptomics analysis we demonstrate that all these proteins, including linkine, are addressed to the shell. Retrieval of motif-forming sequences, such as chitin-binding, with functional annotation from several peptides nested in the shell could indicate protein involvement in shell patterning.
Collapse
Affiliation(s)
- Sophie Berland
- UMR BOREA (Biologie des Organismes et Ecosystèmes Aquatiques), MNHN/CNRS 7208/IRD 207, CP 26, 43 rue Cuvier, 75231 Paris Cedex 05, France.
| | | | | | | | | | | |
Collapse
|
38
|
Resch E, Hiss JA, Schreiner A, Schneider G, Starzinski-Powitz A. Long signal peptides of RGMa and DCBLD2 are dissectible into subdomains according to the NtraC model. ACTA ACUST UNITED AC 2011; 7:942-51. [DOI: 10.1039/c0mb00254b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
39
|
El-Sayed W, Shore RC, Parry DA, Inglehearn CF, Mighell AJ. Hypomaturation amelogenesis imperfecta due to WDR72 mutations: a novel mutation and ultrastructural analyses of deciduous teeth. Cells Tissues Organs 2010; 194:60-6. [PMID: 21196691 PMCID: PMC3128158 DOI: 10.1159/000322036] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Mutations in WDR72 have been identified in autosomal recessive hypomaturation amelogenesis imperfecta (AI). OBJECTIVE to describe a novel WDR72 mutation and report the ultrastructural enamel phenotype associated with a different WDR72 mutation. METHODS A family segregating autosomal recessive hypomaturation AI was recruited, genomic DNA obtained and WDR72 sequenced. Four deciduous teeth from one individual with a previously published WDR72 mutation, extracted as part of clinical care, were subjected to scanning electron microscopy, energy-dispersive X-ray analysis and transverse microradiography. RESULTS A novel homozygous nonsense mutation, R897X, was identified in WDR72 in a family originating from Pakistan. Ultrastructural analysis of enamel from the deciduous teeth of an AI patient with the WDR72 mutation S783X revealed energy-dispersive X-ray analysis spectra with normal carbon and nitrogen peaks, excluding retention of enamel matrix protein. However, transverse microradiography values were significantly lower for affected teeth when compared to normal teeth, consistent with reduced mineralisation. On scanning electron microscopy the enamel rod form observed was normal, yet with inter-rod enamel more prominent than in controls. This appearance was unaltered following incubation with either α-chymotrypsin or lipase. CONCLUSIONS The novel WDR72 mutation described brings the total reported WDR72 mutations to four. Analyses of deciduous tooth enamel in an individual with a homozygous WDR72 mutation identified changes consistent with a late failure of enamel maturation without retention of matrix proteins. The mechanisms by which intracellular WDR72 influences enamel maturation remain unknown.
Collapse
Affiliation(s)
- W El-Sayed
- Leeds Dental Institute, University of Leeds, Leeds, UK
| | | | | | | | | |
Collapse
|
40
|
Pavlopoulou A, Pampalakis G, Michalopoulos I, Sotiropoulou G. Evolutionary history of tissue kallikreins. PLoS One 2010; 5:e13781. [PMID: 21072173 PMCID: PMC2967472 DOI: 10.1371/journal.pone.0013781] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 10/08/2010] [Indexed: 12/12/2022] Open
Abstract
The gene family of human kallikrein-related peptidases (KLKs) encodes proteins with diverse and pleiotropic functions in normal physiology as well as in disease states. Currently, the most widely known KLK is KLK3 or prostate-specific antigen (PSA) that has applications in clinical diagnosis and monitoring of prostate cancer. The KLK gene family encompasses the largest contiguous cluster of serine proteases in humans which is not interrupted by non-KLK genes. This exceptional and unique characteristic of KLKs makes them ideal for evolutionary studies aiming to infer the direction and timing of gene duplication events. Previous studies on the evolution of KLKs were restricted to mammals and the emergence of KLKs was suggested about 150 million years ago (mya). In order to elucidate the evolutionary history of KLKs, we performed comprehensive phylogenetic analyses of KLK homologous proteins in multiple genomes including those that have been completed recently. Interestingly, we were able to identify novel reptilian, avian and amphibian KLK members which allowed us to trace the emergence of KLKs 330 mya. We suggest that a series of duplication and mutation events gave rise to the KLK gene family. The prominent feature of the KLK family is that it consists of tandemly and uninterruptedly arrayed genes in all species under investigation. The chromosomal co-localization in a single cluster distinguishes KLKs from trypsin and other trypsin-like proteases which are spread in different genetic loci. All the defining features of the KLKs were further found to be conserved in the novel KLK protein sequences. The study of this unique family will further assist in selecting new model organisms for functional studies of proteolytic pathways involving KLKs.
Collapse
Affiliation(s)
- Athanasia Pavlopoulou
- Department of Pharmacy, School of Health Sciences, University of Patras, Rion-Patras, Greece
| | - Georgios Pampalakis
- Department of Pharmacy, School of Health Sciences, University of Patras, Rion-Patras, Greece
| | | | - Georgia Sotiropoulou
- Department of Pharmacy, School of Health Sciences, University of Patras, Rion-Patras, Greece
- * E-mail:
| |
Collapse
|
41
|
Chan HC, Mai L, Oikonomopoulou A, Chan HL, Richardson AS, Wang SK, Simmer JP, Hu JCC. Altered enamelin phosphorylation site causes amelogenesis imperfecta. J Dent Res 2010; 89:695-9. [PMID: 20439930 DOI: 10.1177/0022034510365662] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Defects in the enamelin gene (ENAM) cause amelogenesis imperfecta (AI). Our objective was to identify the genetic etiology of enamel hypoplasia in a Caucasian proband. Our hypothesis was that ENAM was defective. The proband and his father have an AG insertion (g.13185_13186insAG; p.422FsX448) in ENAM previously identified in AI kindreds from Slovenia and Turkey. The proband, his brother, and his mother have a novel missense mutation (g.12573C>T) that substitutes leucine for a phosphorylated serine (p.S216L) in the 32-kDa enamelin cleavage product. In this family, a defect in one ENAM allele caused minor pitting or localized enamel hypoplasia, whereas defects in both alleles caused severe enamel malformations, with little or no mineral covering dentin. Ser(216) is one of two serines on the 32-kDa enamelin that is phosphorylated by Golgi casein kinase and is thought to mediate calcium binding. We propose that phosphorylation of enamelin is critical for its function.
Collapse
Affiliation(s)
- H-C Chan
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N. University, Ann Arbor, MI 48109-1078, USA
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Al-Hashimi N, Lafont AG, Delgado S, Kawasaki K, Sire JY. The enamelin genes in lizard, crocodile, and frog and the pseudogene in the chicken provide new insights on enamelin evolution in tetrapods. Mol Biol Evol 2010; 27:2078-94. [PMID: 20403965 DOI: 10.1093/molbev/msq098] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Enamelin (ENAM) has been shown to be a crucial protein for enamel formation and mineralization. Previous molecular analyses have indicated a probable origin early in vertebrate evolution, which is supported by the presence of enamel/enameloid tissues in early vertebrates. In contrast to these hypotheses, ENAM was only characterized in mammals. Our aims were to 1) look for ENAM in representatives of nonmammalian tetrapods, 2) search for a pseudogene in the chicken genome, and 3) see whether the new sequences could bring new information on ENAM evolution. Using in silico approach and polymerase chain reaction, we obtained and characterized the messenger RNA sequences of ENAM in a frog, a lizard, and a crocodile; the genomic DNA sequences of ENAM in a frog and a lizard; and the putative sequence of chicken ENAM pseudogene. The comparison with mammalian ENAM sequences has revealed 1) the presence of an additional coding exon, named exon 8b, in sauropsids and marsupials, 2) a simpler 5'-untranslated region in nonmammalian ENAMs, 3) many sequence variations in the large exons while there are a few conserved regions in small exons, and 4) 25 amino acids that have been conserved during 350 million years of tetrapod evolution and hence of crucial biological importance. The chicken pseudogene was identified in a region that was not expected when considering the gene synteny in mammals. Together with the location of lizard ENAM in a homologous region, this result indicates that enamel genes were probably translocated in an ancestor of the sauropsid lineage. This study supports the origin of ENAM earlier in vertebrate evolution, confirms that tooth loss in modern birds led to the invalidation of enamel genes, and adds information on the important role played by, for example, the phosphorylated serines and the glycosylated asparagines for correct ENAM functions.
Collapse
Affiliation(s)
- Nawfal Al-Hashimi
- Université Pierre et Marie Curie, UMR 7138-Systématique-Adaptation-Evolution, Paris, France
| | | | | | | | | |
Collapse
|