Balodimos I A, Rapaport E, Kashket E R
Department of Microbiology, Boston University School of Medicine, Massachusetts 02118.
Appl Environ Microbiol. 1990 Jul;56(7):2170-3. doi: 10.1128/aem.56.7.2170-2173.1990.
The possible involvement of protein phosphorylation in the clostridial stress response was investigated by radioactively labeling growing cells of Clostridium acetobutylicum with 32Pi or cell extracts with [gamma-32P]ATP. Several phosphoproteins were identified; these were not affected by the growth stage of the culture. Although the extent of protein phosphorylation was increased by heat stress, the phosphoproteins did not correspond to known stress proteins seen in one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purified clostridial DnaK, a stress protein, acted as a kinase catalyzing the phosphorylation of a 50-kilodalton protein. The phosphorylation of this protein was enhanced in extracts prepared from heat-stressed cells. Diadenosine-5',5"'-P1,P4-tetraphosphate had no influence on protein phosphorylation.
通过用³²Pi对丙酮丁醇梭菌的生长细胞进行放射性标记或用[γ-³²P]ATP对细胞提取物进行标记，研究了蛋白质磷酸化在梭菌应激反应中的可能作用。鉴定出了几种磷酸化蛋白；这些蛋白不受培养物生长阶段的影响。尽管热应激会增加蛋白质磷酸化的程度，但在一维十二烷基硫酸钠-聚丙烯酰胺凝胶电泳中，这些磷酸化蛋白与已知的应激蛋白并不对应。纯化的梭菌DnaK（一种应激蛋白）可作为一种激酶，催化一种50千道尔顿蛋白的磷酸化。在热应激细胞制备的提取物中，这种蛋白的磷酸化增强。5',5'''-P1,P4-四磷酸二腺苷对蛋白质磷酸化没有影响。
