N^(6)-甲基腺嘌呤(N6-methyladenine,m^(6)A)修饰作为信使RNA中广泛存在的一种甲基化修饰,它的动态变化在生命活动和疾病的发生发展中发挥着重要的作用。近年来研究发现,通过改变靶基因的m6A修饰水平可以调控肿瘤的进展,因此,通过小分...N^(6)-甲基腺嘌呤(N6-methyladenine,m^(6)A)修饰作为信使RNA中广泛存在的一种甲基化修饰,它的动态变化在生命活动和疾病的发生发展中发挥着重要的作用。近年来研究发现,通过改变靶基因的m6A修饰水平可以调控肿瘤的进展,因此,通过小分子靶向干预m^(6)A去甲基化酶可作为抗肿瘤的新策略。本文重点讨论了m^(6)A去甲基化酶,包括脂肪含量与肥胖相关蛋白(fat mass and obesity-associated protein,FTO)和AlkB同源蛋白5(AlkB homlog5,ALKBH5)的作用方式以及它们在肿瘤中发挥的生物学功能,并总结了m^(6)A去甲基化酶小分子抑制剂的研究进展。展开更多
Seven different, but highly conserved 14-3-3 proteins are involved in diverse signaling pathways in human cells. It isunclear how the 14-3-3σ isoform, a transcriptional target of p53, exerts its inhibitory effect on ...Seven different, but highly conserved 14-3-3 proteins are involved in diverse signaling pathways in human cells. It isunclear how the 14-3-3σ isoform, a transcriptional target of p53, exerts its inhibitory effect on the cell cycle in thepresence of other 14-3-3 isoforms, which are constitutively expressed at high levels. In order to identify structuraldifferences between the 14-3-3 isoforms, we solved the crystal structure of the human 14-3-3σ protein at a resolutionof 2.8 ? and compared it to the known structures of 14-3-3ζ and 14-3-3τ. The global architecture of the 14-3-3σ foldis similar to the previously determined structures of 14-3-3ζ and 14-3-3τ: two 14-3-3σ molecules form a cup-shapeddimer. Significant differences between these 14-3-3 isoforms were detected adjacent to the amphipathic groove, whichmediates the binding to phosphorylated consensus motifs in 14-3-3-ligands. Another specificity determining region islocalized between amino-acids 203 to 215. These differences presumably select for the interaction with specific ligands,which may explain the different biological functions of the respective 14-3-3 isoforms. Furthermore, the two 14-3-3σmolecules forming a dimer differ by the spatial position of the ninth helix, which is shifted to the inside of the ligandinteraction surface, thus indicating adaptability of this part of the molecule. In addition, 5 non-conserved residues arelocated at the interface between two 14-3-3σ proteins forming a dimer and represent candidate determinants of homo-and hetero-dimerization specificity. The structural differences among the 14-3-3 isoforms described here presumablycontribute to isoform-specific interactions and functions.展开更多
文摘N^(6)-甲基腺嘌呤(N6-methyladenine,m^(6)A)修饰作为信使RNA中广泛存在的一种甲基化修饰,它的动态变化在生命活动和疾病的发生发展中发挥着重要的作用。近年来研究发现,通过改变靶基因的m6A修饰水平可以调控肿瘤的进展,因此,通过小分子靶向干预m^(6)A去甲基化酶可作为抗肿瘤的新策略。本文重点讨论了m^(6)A去甲基化酶,包括脂肪含量与肥胖相关蛋白(fat mass and obesity-associated protein,FTO)和AlkB同源蛋白5(AlkB homlog5,ALKBH5)的作用方式以及它们在肿瘤中发挥的生物学功能,并总结了m^(6)A去甲基化酶小分子抑制剂的研究进展。
文摘Seven different, but highly conserved 14-3-3 proteins are involved in diverse signaling pathways in human cells. It isunclear how the 14-3-3σ isoform, a transcriptional target of p53, exerts its inhibitory effect on the cell cycle in thepresence of other 14-3-3 isoforms, which are constitutively expressed at high levels. In order to identify structuraldifferences between the 14-3-3 isoforms, we solved the crystal structure of the human 14-3-3σ protein at a resolutionof 2.8 ? and compared it to the known structures of 14-3-3ζ and 14-3-3τ. The global architecture of the 14-3-3σ foldis similar to the previously determined structures of 14-3-3ζ and 14-3-3τ: two 14-3-3σ molecules form a cup-shapeddimer. Significant differences between these 14-3-3 isoforms were detected adjacent to the amphipathic groove, whichmediates the binding to phosphorylated consensus motifs in 14-3-3-ligands. Another specificity determining region islocalized between amino-acids 203 to 215. These differences presumably select for the interaction with specific ligands,which may explain the different biological functions of the respective 14-3-3 isoforms. Furthermore, the two 14-3-3σmolecules forming a dimer differ by the spatial position of the ninth helix, which is shifted to the inside of the ligandinteraction surface, thus indicating adaptability of this part of the molecule. In addition, 5 non-conserved residues arelocated at the interface between two 14-3-3σ proteins forming a dimer and represent candidate determinants of homo-and hetero-dimerization specificity. The structural differences among the 14-3-3 isoforms described here presumablycontribute to isoform-specific interactions and functions.
