Reconstituted plant uncoupling mitochondrial protein allows for proton translocation via fatty acid cycling mechanism
Jazyk angličtina Země Spojené státy americké Médium print
Typ dokumentu časopisecké články, práce podpořená grantem
PubMed
9305881
DOI
10.1074/jbc.272.39.24272
PII: S0021-9258(19)63594-5
Knihovny.cz E-zdroje
- MeSH
- biologický transport MeSH
- iontové kanály MeSH
- kinetika MeSH
- kyseliny sulfonové metabolismus MeSH
- mastné kyseliny metabolismus MeSH
- membránové proteiny metabolismus MeSH
- mitochondriální proteiny MeSH
- proteolipidy metabolismus MeSH
- protony MeSH
- Solanum lycopersicum metabolismus MeSH
- Solanum tuberosum metabolismus MeSH
- transportní proteiny metabolismus MeSH
- uncoupling protein 1 MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- iontové kanály MeSH
- kyseliny sulfonové MeSH
- mastné kyseliny MeSH
- membránové proteiny MeSH
- mitochondriální proteiny MeSH
- proteolipidy MeSH
- proteoliposomes MeSH Prohlížeč
- protony MeSH
- transportní proteiny MeSH
- uncoupling protein 1 MeSH
Potato and tomato plant uncoupling mitochondrial protein (PUMP) was reconstituted into liposomes, and K+ or H+ fluxes associated with fatty acid (FA)-induced ion movement were measured using fluorescent ion indicators potassium binding benzofuraneisophthalate and 6-methoxy-N-(3-sulfopropyl)-quinolinium. We suggest that PUMP, like its mammalian counterpart, the uncoupling protein of brown adipose tissue mitochondria (Garlid, K. D., Orosz, D. E., Modrianský, M., Vassanelli, S., and Jeek, P. (1996), J. Biol. Chem. 271, 2615-2702), allows for H+ translocation via a FA cycling mechanism. Reconstituted PUMP translocated anionic linoleic and heptylbenzoic acids, undecanesulfonate, and hexanesulfonate, but not phenylvaleric and abscisic acids or Cl-. Transport was inhibited by ATP and GDP. Internal acidification of protein-free liposomes by linoleic or heptylbenzoic acid indicated that H+ translocation occurs by FA flip-flopping across the lipid bilayer. However, addition of valinomycin after FA-initiated GDP-sensitive H+ efflux solely in proteoliposomes, indicating that influx of anionic FA via PUMP precedes a return of protonated FA carrying H+. Phenylvaleric acid, unable to flip-flop, was without effect. Kinetics of FA and undecanesulfonate uniport suggested the existence of an internal anion binding site. Exponential flux-voltage characteristics were also studied. We suggest that regulated uncoupling in plant mitochondria may be important during fruit ripening, senescence, and seed dormancy.
Citace poskytuje Crossref.org
Channel character of uncoupling protein-mediated transport