Abstract：
Melanocyte differentiation is orchestrated by the master regulator transcription factor MITF. However, its ability to discern distinct binding sites linked to effective gene regulation remains poorly understood. This study aims to assess how co-activator acetyltransferase interacts with MITF to modulate their related lysine action, thereby mediating downstream gene regulation, including DNA affinity, stability, transcriptional activity, particularly in the process of shell pigmentation. Here, we have demonstrated that the CgMITF protein can be acetylated, further enabling selective amplification of the melanocyte maturation program. Collaboration with transcriptional co-regulator p300 advances MITF dynamically interplay with downstream targeted gene promoters. We have established that MITF activation was partially dependent on the bHLH domain, which was well conserved across species. The bHLH domain contained conserved lysine residues, including K6 and K43, which interacted with the E-box motif of downstream targeted-genes. Mutations at K6 and K43 lead to a decrease in the binding affinity of the E-box motif. CgMITF protein bound to the E-box motif within the promoter regions of the tyrosinase-related genes, contributing to melanogenesis, and also interacted with the E-box motif within the TBX2 promoter regions, associated with melanocyte proliferation. We elucidated how the bHLH domain links the transcriptional regulation and acetylation modifications in the melanocyte development in C. gigas.
摘要：
黑素细胞分化由主调节转录因子MITF协调。然而,它辨别与有效基因调控相关的不同结合位点的能力仍然知之甚少。本研究旨在评估共激活剂乙酰转移酶如何与MITF相互作用以调节其相关的赖氨酸作用。从而介导下游基因调控，包括DNA亲和力，稳定性,转录活性，特别是在外壳色素沉着的过程中。这里,我们已经证明CgMITF蛋白可以被乙酰化，进一步实现黑素细胞成熟程序的选择性扩增。与转录共调节因子p300的协作使MITF动态地与下游靶向基因启动子相互作用。我们已经确定MITF激活部分依赖于bHLH域,在不同物种之间保存良好。bHLH结构域含有保守的赖氨酸残基，包括K6和K43，它们与下游靶向基因的E盒基序相互作用。K6和K43处的突变导致E盒基序的结合亲和力降低。CgMITF蛋白与酪氨酸酶相关基因启动子区域内的E-box基序结合，有助于黑色素生成，并且还与TBX2启动子区域内的E盒基序相互作用，与黑素细胞增殖有关。我们阐明了bHLH结构域如何连接C.gigas中黑素细胞发育中的转录调节和乙酰化修饰。
