cDNA cloning of S100 calcium-binding proteins from bovine periodontal ligament and their expression in oral tissues.
The periodontal ligament (PDL) is a unique tissue that is crucial for tooth function. However, little is known of the molecular mechanisms controlling PDL function. To characterize PDL cells at the molecular level, we constructed a cDNA library from bovine PDL tissue. We then focused on the isolation of S100 calcium-binding proteins (CaBPs), because they mediate Ca2+ signaling and control important cellular processes such as differentiation and metabolism. We screened the PDL cDNA library with a mouse S100A4 cDNA, and cloned the bovine cDNAs of two S100 CaBPs (S100A4 and S100A2). In northern blotting analysis, the highest expression of S100A4 was detected in PDL from erupted teeth (PDLE). PDL from teeth under eruption (PDLU) showed a lower expression of S100A4, and its expression in gingiva was faintly detectable. S100A4 expression was also high in the pulp tissue followed by the dental papilla of the tooth germ. S100A2 expression was high in PDLE and gingiva. Interestingly, only PDLE exhibited a high expression of both S100A4 and S100A2. PDLE also expressed the highest level of beta-actin, a target cytoskeletal protein for S100A4. It is conceivable that the high expression of S100A4 in PDLE is a result of the maturation of the PDL and/or a response to mechanical stress generated by mastication. Since there was a marked difference of S100A4 expression between PDL and gingiva, we propose that S100A4 could be a useful marker for distinguishing cells from these two tissues.
Department of Periodontology, Faculty of Dentistry, Tokyo Medical and Dental University, Japan.
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Duarte
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Kasugai
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Iimura
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Oida
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Takenaga
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Ohya
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Ishikawa
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000235:genetics* / Q000302:isolation & purification; D002417:Cattle; D003001:Cloning, Molecular / Q000379:methods*; D018076:DNA, Complementary / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics*; D015723:Gene Library; D008334:Mandible; D051379:Mice; D008969:Molecular Sequence Data; D009055:Mouth / Q000737:chemistry / Q000378:metabolism*; D010513:Periodontal Ligament / Q000737:chemistry / Q000378:metabolism*; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; D012689:Sequence Homology, Nucleic Acid
D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; C499413:S100A4 protein, Bos taurus; C470944:S100a4 protein, mouse