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The Fam50a positively regulates ameloblast differentiation via interacting with Runx2
Author(s) -
Kim Yuri,
Hur SungWoong,
Jeong ByungChul,
Oh SinHye,
Hwang YunChan,
Kim SunHun,
Koh JeongTae
Publication year - 2018
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.26038
Subject(s) - ameloblast , amelogenin , microbiology and biotechnology , runx2 , transactivation , gene knockdown , matrix (chemical analysis) , biology , enamel paint , chemistry , transcription factor , cell culture , gene , genetics , dentistry , medicine , chromatography
Differentiated ameloblasts secret enamel matrix proteins such as amelogenin, ameloblastin, and enamelin. Expression levels of these proteins are regulated by various factors. To find a new regulatory factor for ameloblast differentiation, we performed 2D‐PAGE analysis using mouse ameloblast lineage cell line (mALCs) cultured with mineralizing medium. Of identified proteins, family with sequence similarity 50 member A (Fam50a) was significantly increased during differentiation of mALCs. Fam50a protein was also highly expressed in secretory ameloblasts of mouse tooth germs. In mALCs cultures, forced expression of Fam50a up‐regulated the expression of enamel matrix protein genes such as amelogenin, ameloblastin, and enamelin. In addition, up‐regulation of Fam50a also increased ALP activity and mineralized nodule formation in a dose‐dependent manner. In contrast, knockdown of Fam50a decreased expression levels of enamel matrix protein genes, ALP activity, and mineralized nodule formation. By fluorescence microscopy, endogenous Fam50a protein was found to be localized to the nucleus of ameloblasts. In addition, Fam50a synergistically increased Ambn transactivation by Runx2. Moreover, Fam50a increased binding affinity of Runx2 to Ambn promoter by physically interacting with Runx2. Taken together, these results suggest Fam50a might be a new positive regulator of ameloblast differentiation.