Open AccessPeptide substrates rapidly modulate expression of dipeptide and oligopeptide permeases in Candida albicans
Author(s) -
Payne J.W.,
BarrettBee K.J.,
Shallow D.A.
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04496.x
Subject(s) - permease , oligopeptide , dipeptide , candida albicans , peptide , chemistry , microbiology and biotechnology , biochemistry , biology , transporter , gene
Summary Previous studies showed that peptide transport activity in Candida albicans was completely repressed by NH 4 + , and that growth on amino acids as sole nitrogen source stimulated transport to a basal level. Here we show that addition of peptide mixtures to culture media gives a further 5‐fold increase in transport of dipeptides and oligopeptides; the effect is specific for peptide transport, amino acid uptake being unaffected. Presence of peptides but not amino acids overrides NH 4 + repression of peptide transport. Step‐up activation of transport activity, caused by addition of peptides to incubation media, and step‐down inhibition that accompanies removal of peptides, occurs rapidly (within 30 min at 28°C). Step‐up is independent of de novo protein synthesis. This substrate‐induced regulation is compatible with a rapid, reversible activation of plasma membrane‐bound peptide permease(s), or a mechanism of endocytosis involving a cycle of insertion and retrieval of preformed permease components. These results are considered in relation to the expression of peptide permeases in vivo, and the development of synthetic anticandidal peptide carrier prodrugs designed to exploit these systems.