Structural and functional conservation between the high-affinity K+ transporters of Saccharomyces uvarum and Saccharomyces cerevisiae.
In Saccharomyces cerevisiae, high-affinity K+ uptake is dependent upon a 180-kDa plasma membrane protein encoded by TRK1 (c-TRK1) [Gaber et al., Mol. Cell. Biol. 8 (1988) 2848-2859)]. Although hybridization with a c-TRK1 probe revealed highly homologous sequences in the genomes of most Saccharomyces species, the TRK1 sequence in S. uvarum (u-TRK1) was detected only under low-stringency conditions. We cloned u-TRK1 and found it to confer high-affinity K+ uptake in S. cerevisiae. A comparison of the inferred amino acid sequences reveals 78% identity and 86% similarity between the two high-affinity transporters. The most highly conserved regions are the putative membrane-spanning domains (95% identical), suggesting that the structure of the transmembrane domains is important for high-affinity K+ transport.
Anderson
J A
JA
Department of Biochemistry, Molecular and Cell Biology, Northwestern University, Evanston, IL 60208.
Best
L A
LA
Gaber
R F
RF
D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D027682:Cation Transport Proteins; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D015342:DNA Probes; D004271:DNA, Fungal / Q000235:genetics; D005800:Genes, Fungal; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010957:Plasmids; D011188:Potassium / Q000378:metabolism; D015183:Restriction Mapping; D012440:Saccharomyces / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid
D002352:Carrier Proteins; D027682:Cation Transport Proteins; D015342:DNA Probes; D004271:DNA, Fungal; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; C068664:TRK1 protein, S cerevisiae; D011188:Potassium