Microphthalmia-associated transcription factor (MITF) is a member of MYC superfamily, associated with melanocyte cells, as it was discovered in depigmented mice. However, over the last years it was found to be involved in many cellular signaling pathways, among which oncogenesis, osteoclast differentiation, and stress response. In mammals, Mitf gene mutations can cause diverse syndromes affecting pigmentation of eyes or skin, bone defects and melanomas. As MITF protein homologs were also found in some invertebrates, we have isolated and characterized the MITF cDNAs from the sea urchin Paracentrotus lividus, referred to as Pl-Mitf. The in silico study of the secondary and tertiary structure of Pl-Mitf protein showed high conserved regions mostly lying in the DNA binding domain. To understand the degree of evolutionary conservation of MITF, a phylogenetic analysis was performed comparing the Pl-Mitf deduced protein with proteins from different animal species. Moreover, the analysis of temporal and spatial expression pattern of Pl-Mitf mRNA showed that it was expressed from the onset of gastrulation of the sea urchin embryo to the pluteus larva, specifically in primary mesenchymes cells (PMCs), the sea urchin skeletogenic cells, and in the forming archenteron, the larval gut precursor. In silico protein–protein interactions analysis was used to understand the association of MITF with other proteins. Our results put in evidence the conservation of the MITF protein among vertebrates and invertebrates and may provide new perspectives on the pathways underlying sea urchin development, even if further functional analyses are needed.

中文翻译：

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MITF：海胆 Paracentrotus lividus 中进化上保守的转录因子

小眼相关转录因子 (MITF) 是 MYC 超家族的成员，与黑色素细胞相关，因为它是在脱色小鼠中发现的。然而，在过去的几年里，人们发现它参与了许多细胞信号通路，其中包括肿瘤发生、破骨细胞分化和应激反应。在哺乳动物中，Mitf 基因突变会导致多种综合征，影响眼睛或皮肤的色素沉着、骨缺损和黑色素瘤。由于在一些无脊椎动物中也发现了 MITF 蛋白同源物，我们已经从海胆 Paracentrotus lividus 中分离并表征了 MITF cDNA，称为 Pl-Mitf。PI-Mitf 蛋白二级和三级结构的计算机模拟研究显示高度保守的区域主要位于 DNA 结合域中。要了解 MITF 的进化守恒程度，进行系统发育分析，将 Pl-Mitf 推导的蛋白质与来自不同动物物种的蛋白质进行比较。此外，对 Pl-Mitf mRNA 时空表达模式的分析表明，它从海胆胚胎的原肠胚形成开始到冥王星幼虫表达，特别是在原代间充质细胞 (PMC)、海胆骨骼细胞、在形成的原肠中，幼虫的肠道前体。计算机蛋白质-蛋白质相互作用分析用于了解 MITF 与其他蛋白质的关联。我们的结果证明了脊椎动物和无脊椎动物中 MITF 蛋白的保守性，并且即使需要进一步的功能分析，也可能为海胆发育的潜在途径提供新的视角。