Muñoz-Centeno M C, McBratney S, Monterrosa A, Byers B, Mann C, Winey M
Service de Biochimie et de Génétique Moléculaire, Commissariat à l'Energie Atomique/Saclay, F-91191 Gif-sur-Yvette, France.
Mol Biol Cell. 1999 Jul;10(7):2393-406. doi: 10.1091/mbc.10.7.2393.
The MPS2 (monopolar spindle two) gene is one of several genes required for the proper execution of spindle pole body (SPB) duplication in the budding yeast Saccharomyces cerevisiae (). We report here that the MPS2 gene encodes an essential 44-kDa protein with two putative coiled-coil regions and a hydrophobic sequence. Although MPS2 is required for normal mitotic growth, some null strains can survive; these survivors exhibit slow growth and abnormal ploidy. The MPS2 protein was tagged with nine copies of the myc epitope, and biochemical fractionation experiments show that it is an integral membrane protein. Visualization of a green fluorescent protein (GFP) Mps2p fusion protein in living cells and indirect immunofluorescence microscopy of 9xmyc-Mps2p revealed a perinuclear localization with one or two brighter foci of staining corresponding to the SPB. Additionally, immunoelectron microscopy shows that GFP-Mps2p localizes to the SPB. Our analysis suggests that Mps2p is required as a component of the SPB for insertion of the nascent SPB into the nuclear envelope.
MPS2(单极纺锤体2)基因是酿酒酵母中正确执行纺锤体极体(SPB)复制所需的几个基因之一。我们在此报告,MPS2基因编码一种必需的44 kDa蛋白,该蛋白具有两个推定的卷曲螺旋区域和一个疏水序列。虽然MPS2是正常有丝分裂生长所必需的,但一些缺失菌株能够存活;这些存活菌株生长缓慢且倍性异常。MPS2蛋白用九个拷贝的myc表位进行标记,生化分级分离实验表明它是一种整合膜蛋白。活细胞中绿色荧光蛋白(GFP)-Mps2p融合蛋白的可视化以及9xmyc-Mps2p的间接免疫荧光显微镜检查显示其定位于核周,有一或两个较亮的染色焦点对应于SPB。此外,免疫电子显微镜显示GFP-Mps2p定位于SPB。我们的分析表明,Mps2p作为SPB的一个组成部分是将新生SPB插入核膜所必需的。