Localization of transcription factor AP-1 family proteins in ameloblast nuclei of the rat incisor.
We examined by immunocytochemistry the localization of the AP-1 family proteins c-Jun, JunB, JunD, c-Fos, FosB, Fra-1, and Fra-2 in rat incisor ameloblasts. Most of the antibodies against AP-1 family proteins, except for c-Fos-specific antibody, labeled ameloblast nuclei. The labeling intensity of the c-Jun, JunD, and Fra-2 antibodies was stronger than that of JunB, FosB, and Fra-1. Antibody reactivities of c-Jun, JunD, and Fra-2 were greatly enhanced during or after the transition zone. Furthermore, c-Jun antibodies labeled maturation ameloblasts in a cyclic pattern, which was correlated with ameloblast modulation. Disruption of ameloblast modulation by colchicine injection resulted in greatly decreased reactivity of the c-Jun antibody in the ameloblast nuclei of the maturation zone. Phospho-specific antibodies to c-Jun labeled ameloblast nuclei only weakly throughout the secretion, transition, and maturation zones. These results suggest that the stage-specific localization of AP-1 in ameloblasts is closely related to tooth enamel formation.
Nishikawa
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Department of Biology, Tsurumi University School of Dental Medicine, Yokohama, Japan. k01711@simail.ne.jp
D000565:Ameloblasts / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D000906:Antibodies; D002467:Cell Nucleus / Q000378:metabolism; D003078:Colchicine / Q000494:pharmacology; D007150:Immunohistochemistry; D007180:Incisor / Q000378:metabolism*; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000276:immunology / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000276:immunology / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018808:Transcription Factor AP-1 / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D003078:Colchicine