Obikane Yui, Toyono Takashi, Kokabu Shoichiro, Matsuyama Kae, Kataoka Shinji, Nakatomi Mitsushiro, Hosokawa Ryuji, Seta Yuji
Division of Oral Reconstruction and Rehabilitation, Department of Oral Functions, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan.
Division of Anatomy, Department of Health Promotion, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan.
J Oral Biosci. 2021 Dec;63(4):420-428. doi: 10.1016/j.job.2021.08.005. Epub 2021 Sep 4.
Myogenic differentiation 1 (Myod1) is involved in the expression of taste receptor type 1 member 1 (Tas1r1) during myogenic differentiation. Further, the target genes of Myod1 participate in transcriptional control, muscle development, and synaptic function. We examined, for the first time, the function of Myod1 in the transcriptional regulation of Tas1r1.
ENCODE chromatin immunoprecipitation and sequencing (ChIP-seq) data of myogenically differentiated C2C12 cells were analyzed to identify the Myod1 and transcription factor 12 (Tcf12) binding sites in the Tas1r1 promoter region. Luciferase reporter assays, DNA affinity precipitation assays, and co-immunoprecipitation assays were also performed to identify the functions of Myod1, Tcf12, and Krüppel-like factor 5 (Klf5).
Based on ENCODE ChIP-seq, Myod1 bound to the Tas1r1 promoter region containing E-boxes 1-3. Luciferase reporter assays revealed that site-directed E-box1 mutations significantly reduced promoter activation induced by Myod1 overexpression. According to the DNA affinity precipitation assay and co-immunoprecipitation assay, Myod1 formed a heterodimer with Tcf12 and bound to E-box1. Further, Klf5 bound to the GT box near E-box1, activating Tas1r1 expression.
During myogenic differentiation, the Myod1/Tcf12 heterodimer, in collaboration with Klf5, binds to E-box1 and activates Tas1r1 expression.
生肌分化1（Myod1）在生肌分化过程中参与味觉受体1型成员1（Tas1r1）的表达。此外，Myod1的靶基因参与转录调控、肌肉发育和突触功能。我们首次研究了Myod1在Tas1r1转录调控中的作用。
分析生肌分化的C2C12细胞的ENCODE染色质免疫沉淀和测序（ChIP-seq）数据，以确定Tas1r1启动子区域中的Myod1和转录因子（TCF12）结合位点。还进行了荧光素酶报告基因测定、DNA亲和沉淀测定和免疫共沉淀测定，以确定Myod1、Tcf12和Krüppel样因子5（Klf5）的功能。
基于ENCODE ChIP-seq，Myod1与包含E-boxes 1-3的Tas1r1启动子区域结合。荧光素酶报告基因测定显示，定点E-box1突变显著降低了Myod1过表达诱导的启动子激活。根据DNA亲和沉淀测定和免疫共沉淀测定，Myod1与Tcf12形成异二聚体并与E-box1结合。此外，Klf5与E-box附近的GT框结合，激活Tas1r1表达。
在生肌分化过程中，Myod1/Tcf12异二聚体与Klf5协同作用，结合E-box1并激活Tas1r1表达。
