Amelogenin Interacts with Cytokeratin-5 in Ameloblasts during Enamel Growth

Ravindranath, Rajeswari M.H.; Basilrose, Rajam M.; Ravindranath, Naren H.; Vaitheesvaran, Bhavapriya

doi:10.1074/jbc.m211184200

Cited by 26 publications

(28 citation statements)

References 36 publications

(63 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the high conservation observed in the hydrophilic regions of amelogenin throughout all mammalian lineages can only be explained by the existence of important selective pressures, in relation to essential roles played by some amino acids in the structure and function of the amelogenin. Indeed these regions, particularly the N-terminal region, contain amino acids that are suspected to be involved in various functions: a phosphorylation site at serine 16 (Fincham et al 1991), ahelices probably form in the region of aa 19-28 (Toyosawa et al 1998), and a tyrosyl motif (aa 33-45, which binds N-acetyl glucosamine and keratins (Ravindranath et al 1999(Ravindranath et al , 2000(Ravindranath et al , 2001(Ravindranath et al , 2003. In addition, this N-terminal region is known to show aggregative properties (Fincham et al 1991).…”

Section: High Conservation Of Residues In the Hydrophilic Domainsmentioning

confidence: 99%

“…Native amelogenin self-assembles to form spherical aggregates, the so-called nanospheres, that are believed to function as structural components directly involved in the matrix-mediated enamel biomineralization (Moradian-Oldak et al 1994a, 2003Wen et al 2001;Snead 2003). In a series of articles, Ravindranath et al (1999Ravindranath et al ( , 2000Ravindranath et al ( , 2001Ravindranath et al ( , 2003 have investigated the possible interactions of amelogenin with the ameloblasts, in particular, with some keratins, through the ligand-binding properties of the C-terminal domain, which binds specifically to N-acetyl glucosamine and to N-acetyl glucosamine-mimicking peptide. Some splice products have also been proposed to be signaling molecules that could play regulatory roles (Veis et al 2000;Veis 2003).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular Evolution of Amelogenin in Mammals

2005

View full text Add to dashboard Cite

Abstract. An evolutionary analysis of mammalian amelogenin, the major protein of forming enamel, was conducted by comparison of 26 sequences (including 14 new ones) representative of the main mammalian lineages. Amelogenin shows highly conserved residues in the hydrophilic N-and C-terminal regions. The central hydrophobic region (most of exon 6) is more variable, but it has conserved a high amount of proline and glutamine located in triplets, PXQ, indicating that these residues play an important role. This region evolves more rapidly, and is less constrained, than the other well-conserved regions, which are subjected to strong constraints. The comparison of the substitution rates in relation to the CpG richness confirmed that the highly conserved regions are subjected to strong selective pressures. The amino acids located at important sites and the residues known to lead to amelogenesis imperfecta when substituted were present in all sequences examined. Evolutionary analysis of the variable region of exon 6 points to a particular zone, rich in either amino acid insertion or deletion. We consider this region a hot spot of mutation for the mammalian amelogenin. In this region, numerous triplet repeats (PXQ) have been inserted recently and independently in five lineages, while most of the hydrophobic exon 6 region probably had its origin in several rounds of triplet insertions, early in vertebrate evolution. The putative ancestral DNA sequence of the mammalian amelogenin was calculated using a maximum likelihood approach. The putative ancestral protein was composed of 177 residues. It already contained all important amino acid positions known to date, its hydrophobic variable region was rich in proline and glutamine, and it contained triplet repeats PXQ as in the modern sequences.

show abstract

Section: High Conservation Of Residues In the Hydrophilic Domainsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Molecular Evolution of Amelogenin in Mammals

2005

View full text Add to dashboard Cite

show abstract

“…Together with the remaining eosin staining, these results indicate that the enamel of the compound mutants still retained organic matrix at the tip of the crown. The tight junction protein ZO-1 and cytoskeletal component keratin 14 were previously localized at the proximal and distal ends of ameloblasts (Joao and Arana-Chavez, 2003;Ravindranath et al, 2003). Ameloblasts both in the nectin-1À/À; nectin-3þ/À and nectin-1þ/À; nectin-3À/À mutants exhibited abnormal localization of ZO-1 and keratin 14.…”

Section: The Function Of Ameloblasts Is Impaired In Nectin Mutantsmentioning

confidence: 99%

Cooperation of nectin‐1 and nectin‐3 is required for normal ameloblast function and crown shape development in mouse teeth

Yoshida

Miyoshi

Takai

et al. 2010

Developmental Dynamics

View full text Add to dashboard Cite

Nectins are immunoglobulin-like cell adhesion proteins and their interactions recruit various cell-cell junctions. Mutations in human NECTIN-1 cause an ectodermal dysplasia syndrome, but Nectin-1 null mice have only slight defects in teeth, suggesting compensation by other nectin(s). We observed overlapping expression of nectin-3 with nectin-1 and enamel abnormality in the nectin-3 mutant. We, therefore, generated nectin-1;nectin-3 compound mutants. However, all teeth developed and no significant dental abnormalities were observed before birth. At postnatal day 10, the upper molars of compound mutants exhibited conical crown shape and retarded enamel maturation. Nectin-1 was expressed in ameloblasts whereas nectin-3 was expressed in neighboring stratum intermedium cells at this stage. The immunohistochemical localization and electron microscopical observations indicated that the desmosomal junctions between stratum intermedium and ameloblasts were significantly reduced. These results suggest that heterophilic interaction between nectin-1 and nectin-3 recruits desmosomal junctions, and that these are required for proper enamel formation. Developmental Dynamics 239:2558-2569,

show abstract

“…Cytokeratin 5 binds to the amelogenin trityrosyl motif peptide (ATMP) sequence of amelogenin and is suspected to play a chaperone role for nascent amelogenin polypeptides. 55 Thus, the reduction of cytokeratin 5 expression would additionally contribute to the enamel defects observed in Msx2 null mice.…”

Section: Physiopathological Triad Of Hypoplastic Enamel Dysplasia In mentioning

confidence: 99%

Enamel Protein Regulation and Dental and Periodontal Physiopathology in Msx2 Mutant Mice

Molla

Descroix

Aïoub

et al. 2010

The American Journal of Pathology

View full text Add to dashboard Cite

Signaling pathways that underlie postnatal dental and periodontal physiopathology are less studied than those of early tooth development. Members of the muscle segment homeobox gene (Msx) family encode homeoproteins that show functional redundancy during development and are known to be involved in epithelial-mesenchymal interactions that lead to crown morphogenesis and ameloblast cell differentiation. This study analyzed the MSX2 protein during mouse postnatal growth as well as in the adult. The analysis focused on enamel and periodontal defects and enamel proteins in Msx2-null mutant mice. In the epithelial lifecycle, the levels of MSX2 expression and enamel protein secretion were inversely related. Msx2؉/؊ mice showed increased amelogenin expression, enamel thickness, and rod size. Msx2 ؊/؊ mice displayed compound phenotypic characteristics of enamel defects, related to both enamel-specific gene mutations (amelogenin and enamelin) in isolated amelogenesis imperfecta, and cell-cell junction elements (laminin 5 and cytokeratin 5) in other syndromes. These effects were also related to ameloblast disappearance, which differed between incisors and molars. In Msx2 ؊/؊ roots, Malassez cells formed giant islands that overexpressed amelogenin and ameloblastin that grew over months. Aberrant expression of enamel proteins is proposed to underlie the regional osteopetrosis and hyperproduction of cellular cementum. These enamel and periodontal phenotypes of Msx2 mutants constitute the first case report of structural and signaling defects associated with enamel protein overexpression in a postnatal context.

show abstract

Amelogenin Interacts with Cytokeratin-5 in Ameloblasts during Enamel Growth

Cited by 26 publications

References 36 publications

Molecular Evolution of Amelogenin in Mammals

Molecular Evolution of Amelogenin in Mammals

Cooperation of nectin‐1 and nectin‐3 is required for normal ameloblast function and crown shape development in mouse teeth

Enamel Protein Regulation and Dental and Periodontal Physiopathology in Msx2 Mutant Mice

Contact Info

Product

Resources

About