Division of Molecular Biotechnology, Department of Physics, Chemistry and Biology, Linköping University, SE-58183 Linköping, Sweden.
Nucleic Acids Res. 2012 Jul;40(13):6353-66. doi: 10.1093/nar/gks263. Epub 2012 Mar 28.
The crucial role of Myc as an oncoprotein and as a key regulator of cell growth makes it essential to understand the molecular basis of Myc function. The N-terminal region of c-Myc coordinates a wealth of protein interactions involved in transformation, differentiation and apoptosis. We have characterized in detail the intrinsically disordered properties of Myc-1-88, where hierarchical phosphorylation of S62 and T58 regulates activation and destruction of the Myc protein. By nuclear magnetic resonance (NMR) chemical shift analysis, relaxation measurements and NOE analysis, we show that although Myc occupies a very heterogeneous conformational space, we find transiently structured regions in residues 22-33 and in the Myc homology box I (MBI; residues 45-65); both these regions are conserved in other members of the Myc family. Binding of Bin1 to Myc-1-88 as assayed by NMR and surface plasmon resonance (SPR) revealed primary binding to the S62 region in a dynamically disordered and multivalent complex, accompanied by population shifts leading to altered intramolecular conformational dynamics. These findings expand the increasingly recognized concept of intrinsically disordered regions mediating transient interactions to Myc, a key transcriptional regulator of major medical importance, and have important implications for further understanding its multifaceted role in gene regulation.
Myc 作为一种癌蛋白和细胞生长的关键调节剂的关键作用，使得理解 Myc 功能的分子基础变得至关重要。c-Myc 的 N 端区域协调了大量参与转化、分化和凋亡的蛋白质相互作用。我们详细描述了 Myc-1-88 的固有无序特性，其中 S62 和 T58 的分层磷酸化调节 Myc 蛋白的激活和破坏。通过核磁共振（NMR）化学位移分析、弛豫测量和 NOE 分析，我们表明，尽管 Myc 占据了非常异质的构象空间，但我们在残基 22-33 和 Myc 同源盒 I（MBI；残基 45-65）中发现了瞬时结构区域；这些区域在 Myc 家族的其他成员中都是保守的。通过 NMR 和表面等离子体共振（SPR）测定，Bin1 与 Myc-1-88 的结合表明，主要结合到 S62 区域，形成一个动态无序和多价的复合物，同时伴随着构象动力学的改变，导致分子内构象动力学的改变。这些发现扩展了越来越多的固有无序区域介导瞬态相互作用的概念，将其应用于 Myc，这是一种具有重要医学意义的关键转录调节剂，并对进一步理解其在基因调控中的多方面作用具有重要意义。
