We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Tellurite uptake by cells of the facultative phototroph Rhodobacter capsulatus is a ΔpH-dependent process
- Authors
Borsetti, Francesca; Toninello, Antonio; Zannoni, Davide
- Abstract
The uptake by light-grown cells of Rhodobacter capsulatus of the highly toxic metalloid oxyanion tellurite (TeO32−) was examined. We show that tellurite is rapidly taken up by illuminated cells in a process which is inhibited by the protonophore carbonyl cyanide-p-trifluoromethoxyphenyl-hydrazone (FCCP) and by the K+/H+ exchanger nigericin. Notably, the light-driven membrane potential (Δψ) is enhanced by K2TeO3≥200 μM. Further, tellurite uptake is largely insensitive to valinomycin, strongly repressed by the sulfhydryl reagent N-ethylethylmaleimide (NEM) and competitively inhibited by phosphate. We conclude that tellurite is transported into cells by a ΔpH-dependent, non-electrogenic process which is likely to involve the phosphate transporter (PiT family).
- Subjects
RHODOBAENUS; SEMIMETALS; TELLURITES
- Publication
FEBS Letters, 2003, Vol 554, Issue 3, p315
- ISSN
0014-5793
- Publication type
Article
- DOI
10.1016/S0014-5793(03)01180-3