del Rey F, Santos T, García-Acha I, Nombela C
J Bacteriol. 1980 Aug;143(2):621-7. doi: 10.1128/jb.143.2.621-627.1980.
A biphasic synthesis of 1,3-beta-glucanase occurred when cells of Saccharomyces cerevisiae AP-1 (a/alpha) were incubated in sporulation medium. The capacity to degrade laminarin increased very slowly during the first 7 h but at a much faster rate thereafter. Changes occurring during the first period were not sporulation specific since the moderate increase in activity against laminarin was insensitive to glutamine and hydroxyurea and also took place in the nonsporulating strain S. cerevisiae AP-1 (alpha/alpha). However, the changes taking place after 7 h must be included in the group of sporulation-specific events since they were inhibited by glucose, glutamine, and hydroxyurea and did not occur in the nonsporulating diploid. Consequently, only when the cells had been incubated for at least 7 h in sporulation medium did full induction of activity against laminarin take place upon shift to a medium which favored vegetative growth. Changes in the relative proportions of the vegetative glucanases, namely, endo- and exo-1,3-beta-glucanase, and the formation of a new sporulation-specific 1,3-beta-glucanase account for the observed events and are the consequence of the expression of the sporulation program.
当酿酒酵母AP - 1（a/α）细胞在产孢培养基中培养时，会发生1,3 - β - 葡聚糖酶的双相合成。在最初的7小时内，降解海带多糖的能力增加非常缓慢，但此后速度要快得多。第一阶段发生的变化并非产孢特异性的，因为针对海带多糖活性的适度增加对谷氨酰胺和羟基脲不敏感，并且在非产孢菌株酿酒酵母AP - 1（α/α）中也会发生。然而，7小时后发生的变化必定属于产孢特异性事件，因为它们受到葡萄糖、谷氨酰胺和羟基脲的抑制，且在非产孢二倍体中不会发生。因此，只有当细胞在产孢培养基中培养至少7小时后，转移到有利于营养生长的培养基时，针对海带多糖的活性才会完全诱导产生。营养型葡聚糖酶（即内切和外切1,3 - β - 葡聚糖酶）相对比例的变化以及一种新的产孢特异性1,3 - β - 葡聚糖酶的形成解释了所观察到的事件，并且是产孢程序表达的结果。
