TY - JOUR

T1 - Substrate specificity and gene expression of the amino acid permeases in Saccharomyces cerevisiae

AU - Regenberg, Birgitte

AU - Düring-Olsen, Louis

AU - Kielland-Brandt, Morten C.

AU - Holmberg, Steen

PY - 1999/1/1

Y1 - 1999/1/1

N2 - All known amino-acid permeases (AAPs) in Saccharomyces cerevisiae belong to a single family of homologous proteins. Genes of 15 AAPs were overexpressed in different strains, and the ability to take up one or more of the 20 common L-α-amino acids was studied in order to obtain a complete picture of the substrate specificity for these permeases. Radiolabelled aminoacid uptake measurements showed that Agplp is a general permease for most uncharged amino acids (Ala, Gly, Ser, Thr, Cys, Met, Phe, Tyr, Ile, Leu, Val, Gln and Asn). Gnp1p, which is closely related to Agplp, has a somewhat less-broad specificity, transporting Leu, Ser, Thr, Cys, Met, Gln and Asn, while Bap2p and Bap3p, which are also closely related to Agplp, are able to transport Ile, Leu, Val, Cys, Met, Phe, Tyr and Trp. All four permeases are transcriptionally induced by an extracellular amino acid, but differ in expression with respect to the nitrogen source. On a non-repressive nitrogen source, AGP1 is induced, while GLN1, BAP2 and BAP3 are not. Except for Dip5p, which is a transporter for Glu, Asp, Gln, Asn, Ser, Ala and Gly, the rest of the permeases exhibit narrow specificity. Tat2p can take up Phe, Trp and Tyr; Put4p can transport Ala, Gly and Pro; while Can1p, Lyp1p and the previously uncharacterized Alp1p are specific for the cationic amino acids. These findings modify the prevalent view that S. cerevisiae only contains one general amino-acid permease Gap1p, and a number of permeases that are specific for a single or a few amino acids.

AB - All known amino-acid permeases (AAPs) in Saccharomyces cerevisiae belong to a single family of homologous proteins. Genes of 15 AAPs were overexpressed in different strains, and the ability to take up one or more of the 20 common L-α-amino acids was studied in order to obtain a complete picture of the substrate specificity for these permeases. Radiolabelled aminoacid uptake measurements showed that Agplp is a general permease for most uncharged amino acids (Ala, Gly, Ser, Thr, Cys, Met, Phe, Tyr, Ile, Leu, Val, Gln and Asn). Gnp1p, which is closely related to Agplp, has a somewhat less-broad specificity, transporting Leu, Ser, Thr, Cys, Met, Gln and Asn, while Bap2p and Bap3p, which are also closely related to Agplp, are able to transport Ile, Leu, Val, Cys, Met, Phe, Tyr and Trp. All four permeases are transcriptionally induced by an extracellular amino acid, but differ in expression with respect to the nitrogen source. On a non-repressive nitrogen source, AGP1 is induced, while GLN1, BAP2 and BAP3 are not. Except for Dip5p, which is a transporter for Glu, Asp, Gln, Asn, Ser, Ala and Gly, the rest of the permeases exhibit narrow specificity. Tat2p can take up Phe, Trp and Tyr; Put4p can transport Ala, Gly and Pro; while Can1p, Lyp1p and the previously uncharacterized Alp1p are specific for the cationic amino acids. These findings modify the prevalent view that S. cerevisiae only contains one general amino-acid permease Gap1p, and a number of permeases that are specific for a single or a few amino acids.

KW - Amino-acid uptake

KW - Transporter

KW - Yeast

UR - http://www.scopus.com/inward/record.url?scp=0033396550&partnerID=8YFLogxK

U2 - 10.1007/s002940050506

DO - 10.1007/s002940050506

M3 - Journal article

C2 - 10654085

AN - SCOPUS:0033396550

VL - 36

SP - 317

EP - 328

JO - Current Genetics

JF - Current Genetics

SN - 0172-8083

IS - 6

ER -