The mitochondrial carriers are a family of transport proteins that, with a few exceptions, are found in the inner membranes of mitochondria. They shuttles metabolites and cofactors through this membrane, and connect cytoplasm functions with others in the matrix. In S. cerevisiae, S-adenosylmethionine (SAM) is synthesized from ATP and methionine by two synthesases, Sam1p and Sam2p, that are both localized exclusively in the cytosol (1). SAM has therefore to be imported into the mitochondria, where it is converted into S-adenosylhomocysteine in methylation reactions of DNA, RNA and proteins, and is required as essential cofactor in the last step of biotin and lipoic acid biosyntheses, which are catalyzed by biotin synthetase (Bio2p) and lipoate synthetatse (Lip5p), respectively. Here we report the identification and functional characterization of the yeast mitochondrial SAM carrier (Sam5p), encoded by YNL003c also known as PET8(2), and of its human ortholog named SAMC, encoded by SLC25A26.
Identification and characterization of the mitochondrial transporter for S-adenosylmethionine in yeast and man
MAROBBIO, CARLO MARYA;AGRIMI, GENNARO;LASORSA F. M;DI NOIA, MARIA ANTONIETTA;FIERMONTE, Giuseppe;
2004-01-01
Abstract
The mitochondrial carriers are a family of transport proteins that, with a few exceptions, are found in the inner membranes of mitochondria. They shuttles metabolites and cofactors through this membrane, and connect cytoplasm functions with others in the matrix. In S. cerevisiae, S-adenosylmethionine (SAM) is synthesized from ATP and methionine by two synthesases, Sam1p and Sam2p, that are both localized exclusively in the cytosol (1). SAM has therefore to be imported into the mitochondria, where it is converted into S-adenosylhomocysteine in methylation reactions of DNA, RNA and proteins, and is required as essential cofactor in the last step of biotin and lipoic acid biosyntheses, which are catalyzed by biotin synthetase (Bio2p) and lipoate synthetatse (Lip5p), respectively. Here we report the identification and functional characterization of the yeast mitochondrial SAM carrier (Sam5p), encoded by YNL003c also known as PET8(2), and of its human ortholog named SAMC, encoded by SLC25A26.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
