Laskowska Ewa, Kuczyńska-Wiśnik Dorota, Bak Monika, Lipińska Barbara
Department of Biochemistry, University of Gdańsk, Kładki 24, 80-822 Gdańsk, Poland.
Curr Microbiol. 2003 Oct;47(4):286-9. doi: 10.1007/s00284-002-4007-z.
Trimethoprim (TMP), an inhibitor of dihydrofolate reductase, decreases the level of tetrahydrofolate supplying one-carbon units for biosynthesis of nucleotides, proteins, and panthotenate. We have demonstrated for the first time that one of the effects of the TMP action in E. coli cells is protein aggregation and induction of heat shock proteins (Hsps). TMP caused induction of DnaK, DnaJ, GroEL, ClpB, and IbpA/B Hsps. Among these Hsps, IbpA/B were most efficiently induced by TMP and coaggregated with the insoluble proteins. Upon folate stress, deletion of the delta ibpA/B operon resulted in increased protein aggregation but did not influence cell viability.
甲氧苄啶（TMP）是二氢叶酸还原酶的抑制剂，它会降低四氢叶酸的水平，而四氢叶酸为核苷酸、蛋白质和泛酸的生物合成提供一碳单位。我们首次证明，TMP作用于大肠杆菌细胞的效应之一是蛋白质聚集和热休克蛋白（Hsps）的诱导。TMP导致DnaK、DnaJ、GroEL、ClpB和IbpA/B热休克蛋白的诱导。在这些热休克蛋白中，IbpA/B最有效地被TMP诱导，并与不溶性蛋白质共聚集。在叶酸应激下，缺失δibpA/B操纵子会导致蛋白质聚集增加，但不影响细胞活力。
