Jansen R P, Dowzer C, Michaelis C, Galova M, Nasmyth K
Research Institute of Molecular Pathology, Vienna, Austria.
Cell. 1996 Mar 8;84(5):687-97. doi: 10.1016/s0092-8674(00)81047-8.
Certain cell types give rise to progeny that adopt different patterns of gene expression in the absence of any differences in their environment. Cells of budding yeast give birth to mother and daughter cells that differ in that only mother cells express the HO endonuclease gene and thereby switch mating types. We describe the identification of five genes, called SHE1-SHE5, that encode cytoplasmic proteins required for mother-specific HO expression. She1p, which is identical to the minimyosin Myo4p, and She3p are not, however, mother-specific proteins. On the contrary, they accumulate in growing buds. She proteins might be required for the transport of factors that promote HO repression from the mother cell into its bud. In an accompanying paper, we show that SHE genes are needed for the accumulation in daughter nuclei of Ash1p, a repressor of HO.
某些细胞类型会产生后代，这些后代在其环境没有任何差异的情况下会采用不同的基因表达模式。出芽酵母细胞会产生母细胞和子细胞，它们的不同之处在于只有母细胞表达HO内切核酸酶基因，从而转换交配型。我们描述了五个基因（称为SHE1 - SHE5）的鉴定，这些基因编码母细胞特异性HO表达所需的细胞质蛋白。然而，与最小肌球蛋白Myo4p相同的She1p和She3p并不是母细胞特异性蛋白。相反，它们在生长的芽中积累。She蛋白可能是促进HO抑制的因子从母细胞运输到其芽中所必需的。在一篇随附论文中，我们表明SHE基因是Ash1p（一种HO阻遏物）在子细胞核中积累所必需的。
