Furuhashi Hirofumi, Nakajima Mikage, Hirose Susumu
Department of Developmental Genetics, National Institute of Genetics, SOKENDAI, Mishima, Shizuoka-ken 411-8540, Japan.
Development. 2006 Nov;133(22):4475-83. doi: 10.1242/dev.02620. Epub 2006 Oct 11.
DNA supercoiling factor (SCF) is a protein capable of generating negative supercoils in DNA in conjunction with topoisomerase II. To clarify the biological functions of SCF, we introduced a heritable SCF RNAi into Drosophila. Upon knockdown of SCF, we observed male lethality and male-specific reduction in the expression levels of X-linked genes. SCF functionally interacts with components of the MSL complex, which are required for dosage compensation via hypertranscription of the male X chromosome. Moreover, SCF colocalizes with the MSL complex along the male X chromosome. Upon overexpression of SCF, the male X chromosome had a bloated appearance. This phenotype was dependent on the histone acetyltransferase MOF and was suppressed by simultaneous overexpression of ISWI. These findings demonstrate that SCF plays a role in transcriptional activation via alteration of chromatin structure and provide evidence that SCF contributes to dosage compensation.
DNA超螺旋因子（SCF）是一种能够与拓扑异构酶II协同在DNA中产生负超螺旋的蛋白质。为了阐明SCF的生物学功能，我们将可遗传的SCF RNA干扰技术引入果蝇。在敲低SCF后，我们观察到雄性致死以及X连锁基因表达水平的雄性特异性降低。SCF在功能上与MSL复合体的组分相互作用，而MSL复合体是通过雄性X染色体的超转录进行剂量补偿所必需的。此外，SCF沿着雄性X染色体与MSL复合体共定位。在SCF过表达时，雄性X染色体呈现肿胀外观。这种表型依赖于组蛋白乙酰转移酶MOF，并被ISWI的同时过表达所抑制。这些发现表明SCF通过改变染色质结构在转录激活中发挥作用，并提供了SCF有助于剂量补偿的证据。
