|Name:||solute carrier family 25 (mitochondrial carrier: glutamate), member 22|
|PubMed (11897791):|| Fiermonte G, Palmieri L, Todisco S, Agrimi G, Palmieri F, Walker JE. Identification of the mitochondrial glutamate transporter. Bacterialexpression, reconstitution, functional characterization, and tissue distributionof two human isoforms.J Biol Chem. 2002 May 31;277(22):19289-94. Epub 2002 Mar 15. PMID: 11897791 [PubMed - indexed for MEDLINE]|
The mitochondrial carriers are a family of transport proteins in the inner membranes of mitochondria. They shuttle substrates, metabolites, and cofactors through this membrane and connect cytoplasm functions with others in the matrix. Glutamate is co-transported with H(+) (or exchanged for OH(-)), but no protein has ever been associated with this activity. Two human expressed sequence tags encode proteins of 323 and 315 amino acids with 63% identity that are related to the aspartate-glutamate carrier, a member of the carrier family. They have been overexpressed in Escherichia coli and reconstituted into phospholipid vesicles. Their transport properties demonstrate that the two proteins are isoforms of the glutamate/H(+) symporter described in the past in whole mitochondria. Isoform 1 is expressed at higher levels than isoform 2 in all the tissues except in brain, where the two isoforms are expressed at comparable levels. The differences in expression levels and kinetic parameters of the two isoforms suggest that isoform 2 matches the basic requirement of all tissues especially with respect to amino acid degradation, and isoform 1 becomes operative to accommodate higher demands associated with specific metabolic functions such as ureogenesis.
>sp|Q9H936|GHC1_HUMAN Mitochondrial glutamate carrier 1 (Glutamate/H(+) symporter 1) (Solute carrier family 25, member 22) - Homo sapiens (Human). MADKQISLPAKLINGGIAGLIGVTCVFPIDLAKTRLQNQQNGQRVYTSMSDCLIKTVRSEGYFGMYRGAAVNLTLVTPEK AIKLAANDFFRHQLSKDGQKLTLLKEMLAGCGAGTCQVIVTTPMEMLKIQLQDAGRIAAQRKILAAQGQLSAQGGAQPSV EAPAAPRPTATQLTRDLLRSRGIAGLYKGLGATLLRDVPFSVVYFPLFANLNQLGRPASEEKSPFYVSFLAGCVAGSAAA VAVNPCDVVKTRLQSLQRGVNEDTYSGILDCARKILRHEGPSAFLKGAYCRALVIAPLFGIAQVVYFLGIAESLLGLLQD PQA