Smith E R, Pannuti A, Gu W, Steurnagel A, Cook R G, Allis C D, Lucchesi J C
Department of Biology, Emory University, Atlanta, Georgia 30322, USA.
Mol Cell Biol. 2000 Jan;20(1):312-8. doi: 10.1128/MCB.20.1.312-318.2000.
In Drosophila, dosage compensation-the equalization of most X-linked gene products in males and females-is achieved by a twofold enhancement of the level of transcription of the X chromosome in males relative to each X chromosome in females. A complex consisting of at least five gene products preferentially binds the X chromosome at numerous sites in males and results in a significant increase in the presence of a specific histone isoform, histone 4 acetylated at lysine 16. Recently, RNA transcripts (roX1 and roX2) encoded by two different genes have also been found associated with the X chromosome in males. We have partially purified a complex containing MSL1, -2, and -3, MOF, MLE, and roX2 RNA and demonstrated that it exclusively acetylates H4 at lysine 16 on nucleosomal substrates. These results demonstrate that the MSL complex is responsible for the specific chromatin modification characteristic of the X chromosome in Drosophila males.
在果蝇中，剂量补偿（即雄性和雌性中大多数X连锁基因产物的均等化）是通过雄性中X染色体转录水平相对于雌性中每条X染色体转录水平提高两倍来实现的。一个由至少五种基因产物组成的复合体在雄性的众多位点优先结合X染色体，并导致一种特定组蛋白异构体（赖氨酸16乙酰化的组蛋白4）的存在显著增加。最近，还发现由两个不同基因编码的RNA转录本（roX1和roX2）与雄性的X染色体相关联。我们已经部分纯化了一个包含MSL1、-2和-3、MOF、MLE以及roX2 RNA的复合体，并证明它专门在核小体底物上使赖氨酸16处的H4乙酰化。这些结果表明，MSL复合体负责果蝇雄性中X染色体特有的染色质修饰。
