TY - JOUR
T1 - Molecular identification and functional characterization of a novel glutamate transporter in yeast and plant mitochondria
AU - Porcelli, Vito
AU - Vozza, Angelo
AU - Calcagnile, Valeria
AU - Gorgoglione, Ruggiero
AU - Arrigoni, Roberto
AU - Fontanesi, Flavia
AU - Marobbio, Carlo M.T.
AU - Castegna, Alessandra
AU - Palmieri, Ferdinando
AU - Palmieri, Luigi
N1 - Funding Information:
The expert technical assistance of Mr. Riccardo Merafina (CNR IBIOM) is acknowledged. This work was supported by grants from the Ministero dell'Istruzione, dell'Università e della Ricerca ( MIUR ), the Center of Excellence on Comparative Genomics ( CEGBA ) and the American Heart Association ( AHA ) [development grant 14SDG20040003 to F.F.].
PY - 2018/11
Y1 - 2018/11
N2 - The genome of Saccharomyces cerevisiae encodes 35 members of the mitochondrial carrier family (MCF) and 58 MCF members are coded by the genome of Arabidopsis thaliana, most of which have been functionally characterized. Here two members of this family, Ymc2p from S. cerevisiae and BOU from Arabidopsis, have been thoroughly characterized. These proteins were overproduced in bacteria and reconstituted into liposomes. Their transport properties and kinetic parameters demonstrate that Ymc2p and BOU transport glutamate, and to a much lesser extent L-homocysteinesulfinate, but not other amino acids and many other tested metabolites. Transport catalyzed by both carriers was saturable, inhibited by mercuric chloride and dependent on the proton gradient across the proteoliposomal membrane. The growth phenotype of S. cerevisiae cells lacking the genes ymc2 and agc1, which encodes the only other S. cerevisiae carrier capable to transport glutamate besides aspartate, was fully complemented by expressing Ymc2p, Agc1p or BOU. Mitochondrial extracts derived from ymc2Δagc1Δ cells, reconstituted into liposomes, exhibited no glutamate transport at variance with wild-type, ymc2Δ and agc1Δ cells, showing that S. cerevisiae cells grown in the presence of acetate do not contain additional mitochondrial transporters for glutamate besides Ymc2p and Agc1p. Furthermore, mitochondria isolated from wild-type, ymc2Δ and agc1Δ strains, but not from the double mutant ymc2Δagc1Δ strain, swell in isosmotic ammonium glutamate showing that glutamate is transported by Ymc2p and Agc1p together with a H+. It is proposed that the function of Ymc2p and BOU is to transport glutamate across the mitochondrial inner membrane and thereby play a role in intermediary metabolism, C1 metabolism and mitochondrial protein synthesis.
AB - The genome of Saccharomyces cerevisiae encodes 35 members of the mitochondrial carrier family (MCF) and 58 MCF members are coded by the genome of Arabidopsis thaliana, most of which have been functionally characterized. Here two members of this family, Ymc2p from S. cerevisiae and BOU from Arabidopsis, have been thoroughly characterized. These proteins were overproduced in bacteria and reconstituted into liposomes. Their transport properties and kinetic parameters demonstrate that Ymc2p and BOU transport glutamate, and to a much lesser extent L-homocysteinesulfinate, but not other amino acids and many other tested metabolites. Transport catalyzed by both carriers was saturable, inhibited by mercuric chloride and dependent on the proton gradient across the proteoliposomal membrane. The growth phenotype of S. cerevisiae cells lacking the genes ymc2 and agc1, which encodes the only other S. cerevisiae carrier capable to transport glutamate besides aspartate, was fully complemented by expressing Ymc2p, Agc1p or BOU. Mitochondrial extracts derived from ymc2Δagc1Δ cells, reconstituted into liposomes, exhibited no glutamate transport at variance with wild-type, ymc2Δ and agc1Δ cells, showing that S. cerevisiae cells grown in the presence of acetate do not contain additional mitochondrial transporters for glutamate besides Ymc2p and Agc1p. Furthermore, mitochondria isolated from wild-type, ymc2Δ and agc1Δ strains, but not from the double mutant ymc2Δagc1Δ strain, swell in isosmotic ammonium glutamate showing that glutamate is transported by Ymc2p and Agc1p together with a H+. It is proposed that the function of Ymc2p and BOU is to transport glutamate across the mitochondrial inner membrane and thereby play a role in intermediary metabolism, C1 metabolism and mitochondrial protein synthesis.
KW - A bout de souffle
KW - C1 metabolism
KW - Mitochondrial carriers
KW - Mitochondrial glutamate carrier
KW - Photorespiration
KW - YMC2
UR - http://www.scopus.com/inward/record.url?scp=85051508777&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85051508777&partnerID=8YFLogxK
U2 - 10.1016/j.bbabio.2018.08.001
DO - 10.1016/j.bbabio.2018.08.001
M3 - Article
C2 - 30297026
AN - SCOPUS:85051508777
VL - 1859
SP - 1249
EP - 1258
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 11
ER -