A proteome analysis of the yeast response to the herbicide 2,4-dichlorophenoxyacetic acid.
Miguel C. Teixeira (1), Pedro M. Santos (1), Alexandra R. Fernandes (2), Isabel Sá-Correia (1)
(1) Biological Sciences Research Group, CEBQ, Instituto Superior Tecnico, 1049-001 Lisbon, Portugal; (2) Biological Sciences Research Group, CEBQ, Instituto Superior Tecnico, 1049-001 Lisbon, Portugal; Universidade Lusófona de Humanidades e Tecnologias, Campo Grande, 376, 1749-029 Lisbon, Portugal
The modifications occurring in the proteome of S. cerevisiae due to aggression by the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) were examined to gain insights into the mechanisms of toxicity and tolerance. During the adaptation period preceding the resumption of inhibited exponential growth under 2,4-D stress, the antioxidant enzyme Ahp1, two heat shock proteins (Hsp12, Ssb1/2) and enzymes involved in protein (Cdc48) and mRNA (Dcp1) degradation and in carbohydrate metabolism were present in higher amounts. This is consistent with the pro-oxidant effect of 2,4-D [2] and increased cell needs to alter protein repertoire and support energy-consuming adaptation mechanisms [3, 4]. The increased amount registered in 2 peripheral subunits of vacuolar H + -ATPase (V-ATPase) in response to the herbicide is consistent with the stimulation of this proton pump activity [4]. A functional V-ATPase is required to counteract the dissipation of the H+-gradient across vacuolar membrane by 2,4-D [4]. The increased content of 7 amino acid biosynthetic enzymes registered in 2,4-D-stressed cells correlated with the reduced amino acid concentration in the vacuole and cytosol, possibly due to the disturbance of vacuolar and plasma membrane functions by this lipophilic acid herbicide. [1] Teixeira et al Proteomics in press [2] Teixeira et al 2004 BBRC 324:1101 [3] Teixeira, Sá-Correia 2002 BBRC 292:530 [4] Fernandes et al 2003 BBRC 312:1317.