Schreiber-Agus N, Chin L, Chen K, Torres R, Rao G, Guida P, Skoultchi A I, DePinho R A
Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461.
Cell. 1995 Mar 10;80(5):777-86. doi: 10.1016/0092-8674(95)90356-9.
Documented interactions among members of the Myc superfamily support a yin-yang model for the regulation of Myc-responsive genes in which transactivation-competent Myc-Max heterodimers are opposed by repressive Mxi1-Max or Mad-Max complexes. Analysis of mouse mxi1 has led to the identification of two mxi1 transcript forms possessing open reading frames that differ in their capacity to encode a short amino-terminal alpha-helical domain. The presence of this segment dramatically augments the suppressive potential of Mxi1 and allows for association with a mammalian protein that is structurally homologous to the yeast transcriptional repressor SIN3. These findings provide a mechanistic basis for the antagonistic actions of Mxi1 on Myc activity that appears to be mediated in part through the recruitment of a putative transcriptional repressor.
Myc超家族成员之间已记录的相互作用支持一种阴阳模型，用于调控Myc反应基因，其中具有转录激活能力的Myc-Max异源二聚体与抑制性的Mxi1-Max或Mad-Max复合物相互对抗。对小鼠mxi1的分析已导致鉴定出两种具有开放阅读框的mxi1转录本形式，它们编码短氨基末端α-螺旋结构域的能力不同。该片段的存在极大地增强了Mxi1的抑制潜力，并允许其与一种在结构上与酵母转录抑制因子SIN3同源的哺乳动物蛋白结合。这些发现为Mxi1对Myc活性的拮抗作用提供了一个机制基础，这种拮抗作用似乎部分是通过募集一种假定的转录抑制因子介导的。
