Krüppel-like factor 4 interacts with p300 to activate mitofusin 2 gene expression induced by all-trans retinoic acid in VSMCs.
OBJECTIVE
To elucidate how krüppel-like factor 4 (KLF4) activates mitofusin 2 (mfn-2) expression in all-trans retinoic acid (ATRA)-induced vascular smooth muscle cell (VSMC) differentiation.


METHODS
The mfn-2 promoter-reporter constructs and the KLF4 acetylation-deficient or phosphorylation-deficient mutants were constructed. Adenoviral vector of KLF4-mediated overexpression and Western blot analysis were used to determine the effect of KLF4 on mfn-2 expression. The luciferase assay and chromatin immunoprecipitation were used to detect the transactivation of KLF4 on mfn-2 gene expression. Co-immunoprecipitation and GST pull-down assays were used to determine the modification of KLF4 and interaction of KLF4 with p300 in VSMCs.


RESULTS
KLF4 mediated ATRA-induced mfn-2 expression in VSMCs. KLF4 bound directly to the mfn-2 promoter and activated its transcription. ATRA increased the interaction of KLF4 with p300 by inducing KLF4 phosphorylation via activation of JNK and p38 MAPK signaling. KLF4 acetylation by p300 increased its activity to transactivate the mfn-2 promoter.


CONCLUSIONS
ATRA induces KLF4 acetylation by p300 and increases the ability of KLF4 to transactivate the mfn-2 promoter in VSMCs.
Zhang
Rui
R
Department of Biochemistry and Molecular Biology, Hebei Medical University, Shijiazhuang, China.
Han
Mei
M
Zheng
Bin
B
Li
Ying-jie
YJ
Shu
Ya-nan
YN
Wen
Jin-kun
JK
D000107:Acetylation; D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D050881:E1A-Associated p300 Protein / Q000235:genetics / Q000378:metabolism*; D020558:GTP Phosphohydrolases; D005786:Gene Expression Regulation; D066298:In Vitro Techniques; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis*; D024101:Mitochondrial Proteins / Q000096:biosynthesis*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D014158:Transcription, Genetic; D014212:Tretinoin / Q000494:pharmacology*; D016335:Zinc Fingers
C000715469:Klf4 protein, rat; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D014212:Tretinoin; D050881:E1A-Associated p300 Protein; C494362:Ep300 protein, rat; D020558:GTP Phosphohydrolases; C489710:Mfn2 protein, rat