WWP2 Promotes Odontoblastic Differentiation by Monoubiquitinating KLF5

被引：19

作者：

Fu, J. ^{[1
,2
]}

Zheng, H. ^{[1
,2
]}

Xue, Y. ^{[1
,2
]}

Jin, R. ^{[1
,2
]}

Yang, G. ^{[1
,2
]}

Chen, Z. ^{[1
,2
]}

Yuan, G. ^{[1
,2
]}

机构：

[1] Wuhan Univ, Sch & Hosp Stomatol, State Key Lab Breeding Base Basic Sci Stomatol, Minist Educ, 237 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China

[2] Wuhan Univ, Sch & Hosp Stomatol, Key Lab Oral Biomed Minist Educ, Minist Educ, 237 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China

来源：

JOURNAL OF DENTAL RESEARCH | 2021年 / 100卷 / 04期

基金：

中国国家自然科学基金;

关键词：

cell differentiation; dentinogenesis; odontoblast(s); tooth development; ubiquitin-protein ligases; ubiquitination;

D O I：

10.1177/0022034520970866

中图分类号：

R78 [口腔科学];

学科分类号：

1003 ;

摘要：

WW domain-containing E3 Ub-protein ligase 2 (WWP2) belongs to the homologous to E6AP C-terminus (HECT) E3 ligase family. It has been explored to regulate osteogenic differentiation, chondrogenesis, and palatogenesis. Odontoblasts are terminally differentiated mesenchymal cells, which contribute to dentin formation in tooth development. However, it remained unknown whether WWP2 participated in odontoblast differentiation. In this study, WWP2 was found to be expressed in mouse dental papilla cells (mDPCs), odontoblasts, and odontoblastic-induced mDPCs by immunohistochemistry and Western blotting. Besides, WWP2 expression was decreased in the cytoplasm but increased in the nuclei of differentiation-induced mDPCs. When Wwp2 was knocked down, the elevated expression of odontoblast marker genes (Dmp1 and Dspp) in mDPCs induced by differentiation medium was suppressed. Meanwhile, a decrease of alkaline phosphatase (ALP) activity was observed by ALP staining, and reduced formation of mineralized matrix nodules was demonstrated by Alizarin Red S staining. Overexpression of WWP2 presented opposite results to knockdown experiments, suggesting that WWP2 promoted odontoblastic differentiation of mDPCs. Further investigation found that WWP2 was coexpressed and interacted with KLF5 in the nuclei, leading to ubiquitination of KLF5. The PPPSY (PY2) motif of KLF5 was essential for its physical binding with WWP2. Also, cysteine 838 (Cys838) of WWP2 was the active site for ubiquitination of KLF5, which did not lead to proteolysis of KLF5. Then, KLF5 was confirmed to be monoubiquitinated and transactivated by WWP2, which promoted the expression of KLF5 downstream genes Dmp1 and Dspp. Deletion of the PY2 motif of KLF5 or mutation of Cys838 of WWP2 reduced the upregulation of Dmp1 and Dspp. Besides, lysine (K) residues K31, K52, K83, and K265 of KLF5 were verified to be crucial to WWP2-mediated KLF5 transactivation. Taken together, WWP2 promoted odontoblastic differentiation by monoubiquitinating KLF5.

引用

页码：432 / 439

页数：8

共 39 条

[1] The E3 ligases Itch and WWP2 cooperate to limit TH2 differentiation by enhancing signaling through the TCR [J].