Borecký J, Maia I G, Costa A D, Jezek P, Chaimovich H, de Andrade P B, Vercesi A E, Arruda P
Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
FEBS Lett. 2001 Sep 14;505(2):240-4. doi: 10.1016/s0014-5793(01)02835-6.
The Arabidopsis thaliana uncoupling protein (UCP) gene was expressed in Escherichia coli and isolated protein reconstituted into liposomes. Linoleic acid-induced H+ fluxes were sensitive to purine nucleotide inhibition with an apparent K(i) (in mM) of 0.8 (GDP), 0.85 (ATP), 0.98 (GTP), and 1.41 (ADP); the inhibition was pH-dependent. Kinetics of AtPUMP1-mediated H+ fluxes were determined for lauric, myristic, palmitic, oleic, linoleic, and linolenic acids. Properties of recombinant AtPUMP1 indicate that it represents a plant counterpart of animal UCP2 or UCP3. This work brings the functional and genetic approaches together for the first time, providing strong support that AtPUMP1 is truly an UCP.
