Natural and azido fatty acids inhibit phosphate transport and activate fatty acid anion uniport mediated by the mitochondrial phosphate carrier

0142202 - FGU-C 20010257 RIV US eng J - Journal Article
Engstová, Hana - Žáčková, Markéta - Růžička, Michal - Meinhardt, A. - Hanuš, Jan - Krämer, R. - Ježek, Petr
Natural and azido fatty acids inhibit phosphate transport and activate fatty acid anion uniport mediated by the mitochondrial phosphate carrier.
Journal of Biological Chemistry. Roč. 276, č. 7 (2001), s. 4683-4691. ISSN 0021-9258. E-ISSN 1083-351X
R&D Projects: GA ČR GA301/95/0620; GA ČR GA301/98/0568; GA MŠMT ME 085; GA MŠMT ME 389
Grant - others:US(US) Czechoslovak Science and Technology Program 94043
Institutional research plan: CEZ:AV0Z5011922
Keywords : phosphate transport * fatty acids
Subject RIV: CE - Biochemistry
Impact factor: 7.258, year: 2001

The electroneutral Pi uptake via the phosphate carrier (PIC) in rat liver and heart mitochondria is inhibited by fatty acids (FAs), by 12-(4-azido-2-nitrophenylamino) dodecanoic (AzDA), heptylbenzoic (M doses); by lauric, palmitic or 12-azidododecanoic acids (0.1 mM doses). In turn, reconstituted E.coli- expressed yeast PIC mediated anionic FA uniport with a similar pattern leading to FA cycling and H+ uniport. Kinetics of Pi/Pi exchange on recombinant PIC in the presence of AzDA better corresponded to a competive inhibition mechanism. Methanephosphonate was identified as a new PIC substrate. Decanephosphonate, butane-phosphonate, 4-nitrophenylphosphate and other Pi analogs were not translocated and did not inhibit Pi transport. However, methylenediphosphonate and iminodi(methylenephosphonate) inhibited both electroneutral Pi uptake and FA cycling via PIC. AzDA analog, 16-(4-azido-2-nitrophenylamino)-[3H4]-hexadecanoic acid (3H-AzHA) bound upon photoactivation to several mitochondrial proteins, including the 30 and 34 kD bands. The latter was ascribed to PIC due to its specific elution pattern on Blue Sepharose and Affi-Gel. 3H-AzHA photolabeling of recombinant PIC was prevented by methanephosphonate, diphosphonates and after premodification with 4-azido-2-nitrophenylphosphate. Hence, the demonstrated PIC interaction with monovalent long-chain FA anions, but with divalent phosphonates of short chain only, indicates a pattern distinct from that valid for the mitochondrial uncoupling protein-1.
Permanent Link: http://hdl.handle.net/11104/0039909