Wang H, Clark I, Nicholson P R, Herskowitz I, Stillman D J
Department of Cellular, Viral and Molecular Biology, University of Utah School of Medicine, Salt Lake City 84132.
Mol Cell Biol. 1990 Nov;10(11):5927-36. doi: 10.1128/mcb.10.11.5927-5936.1990.
The SIN3 gene (also known as SDI1) is a negative regulator of the yeast HO gene. Mutations in SIN3 suppress the requirement for the SWI5 activator for expression of the yeast HO gene and change the normal asymmetric pattern of HO expression in mother and daughter cells. Furthermore, the in vitro DNA-binding activity of several DNA-binding proteins is reduced in extracts prepared from sin3 mutants. We have cloned the SIN3 gene and determined that a haploid strain with a SIN3 gene disruption is viable. We determined the sequence of the SIN3 gene, which is predicted to encode a 175-kDa polypeptide with four paired amphipathic helix motifs. These motifs have been identified in the myc family of helix-loop-helix DNA-binding proteins and in the TPR family of regulatory proteins. The SIN3 transcript was mapped, and it was determined that the SIN3 transcript was absent in stationary-phase cells. Immunofluorescence microscopy with anti-SIN3 antibody demonstrated that SIN3 protein was present in nuclei. A comparison of restriction map and sequence data revealed that SIN3 is the same as regulatory genes UME4 and RPD1.
SIN3基因（也称为SDI1）是酵母HO基因的负调控因子。SIN3基因的突变抑制了酵母HO基因表达对SWI5激活因子的需求，并改变了HO基因在母细胞和子细胞中正常的不对称表达模式。此外，从sin3突变体提取物中制备的几种DNA结合蛋白的体外DNA结合活性降低。我们克隆了SIN3基因，并确定了一个SIN3基因被破坏的单倍体菌株是可存活的。我们测定了SIN3基因的序列，预计该基因编码一个具有四个成对两亲性螺旋基序的175 kDa多肽。这些基序已在螺旋-环-螺旋DNA结合蛋白的myc家族和调节蛋白的TPR家族中被鉴定出来。绘制了SIN3转录本图谱，并确定在稳定期细胞中不存在SIN3转录本。用抗SIN3抗体进行免疫荧光显微镜检查表明，SIN3蛋白存在于细胞核中。限制性图谱和序列数据的比较表明，SIN3与调控基因UME4和RPD1相同。
