Wright J F, Ajam N, Dawes I W
Mol Cell Biol. 1981 Oct;1(10):910-8. doi: 10.1128/mcb.1.10.910-918.1981.
During meiosis and spore formulation in Saccharomyces cerevisiae, changes that occur in a/alpha diploids, but not in isogenic nonsporulating a/a diploids, have been detected in cellular polypeptides. These were found by the technique of prelabeling growing cells with 35SO4(2-) and suspending them in sulfur-free sporulation medium. Under the conditions used, about 400 polypeptides were detected by two-dimensional gel electrophoresis, and 45 were altered during sporulation; of these, 21 changes were specific to a/alpha strains. These alterations were mainly due to the appearance of new polypeptides or to marked increases in the concentrations of a few polypeptides produced during vegetative growth. They could have been due either to modifications of existing polypeptides present in growing cells or to de novo synthesis of new gene products. They occurred at characteristic times during sporulation; whereas the majority of changes took place early (within the first 6 h in sporulation conditions), there were several changes characterizing the later stages of sporulation. Ten of the 35SO4(2-)-labeled polypeptides were also labeled with 32P in the presence of [32P]orthophosphate; of these, three were previously found to be sporulation specific. One of these was phosphorylated at all stages of sporulation and was labeled when [32P]orthophosphate was added either during growth of the culture of 1 h after transfer to sporulation medium. Another was labeled in the same way by adding 32P at either time, so that by 7 h in sporulation medium it was phosphorylated, but was dephosphorylated by 24 h. The third sporulation-specific peptide was labeled in extracts prepared at 7 h in sporulation medium (but not at 24 h) when [32P]-orthophosphate was added during presporulation growth, but not when [32P]-orthophosphate was added 1 h after transfer of the culture to sporulation medium. This polypeptide appeared early during sporulation; it is probably phosphorylated as it appears and is dephosphorylated at some time between 7 h and 24 h of sporulation.
在酿酒酵母减数分裂和孢子形成过程中，已在细胞多肽中检测到a/α二倍体发生的变化，而等基因的不产孢a/a二倍体则未出现这种变化。这些变化是通过用35SO4(2-)预标记生长中的细胞并将其悬浮于无硫孢子形成培养基中的技术发现的。在所使用的条件下，通过二维凝胶电泳检测到约400种多肽，其中45种在孢子形成过程中发生了改变；其中，21种变化是a/α菌株特有的。这些改变主要是由于新多肽的出现或营养生长期间产生的少数几种多肽浓度的显著增加。它们可能是由于生长细胞中现有多肽的修饰，也可能是新基因产物的从头合成。它们在孢子形成过程中的特定时间出现；虽然大多数变化发生在早期（在孢子形成条件下的前6小时内），但也有一些变化是孢子形成后期的特征。35SO4(2-)标记的多肽中有10种在[32P]正磷酸盐存在的情况下也被32P标记；其中，三种先前被发现是孢子形成特异性的。其中一种在孢子形成的所有阶段都被磷酸化，并且当在培养物生长期间或转移到孢子形成培养基后1小时添加[32P]正磷酸盐时被标记。另一种在两个时间点以相同方式被标记，因此在孢子形成培养基中培养7小时时它被磷酸化，但在24小时时去磷酸化。第三种孢子形成特异性肽在孢子形成培养基中培养7小时（但不是24小时）制备的提取物中被标记，前提是在孢子形成前生长期间添加[32P]正磷酸盐，但在培养物转移到孢子形成培养基后1小时添加[32P]正磷酸盐时则未被标记。这种多肽在孢子形成早期出现；它可能在出现时被磷酸化，并在孢子形成7小时至24小时之间的某个时间去磷酸化。
