Characterization of the Amino Acid Permease Family: Gap2 Is the Only General Amino Acid Permease and Gap4 Is an -Adenosylmethionine (SAM) Transporter Required for SAM-Induced Morphogenesis.

Amino acids are key sources of nitrogen for growth of . In order to detect and take up these amino acids from a broad range of different and changing nitrogen sources inside the host, this fungus must be able to adapt via its expression of genes for amino acid uptake and further metabolism. We analyzed six putative general amino acid permeases based on their homology to the Gap1 general amino acid permease. We generated single- and multiple-deletion strains and found that, based on growth assays and transcriptional or posttranscriptional regulation, Gap2 is the functional orthologue to Gap1, with broad substrate specificity. Expression analysis showed that expression of all genes is under control of the Csy1 amino acid sensor, which is different from the situation in , where the expression of is not regulated by Ssy1. We show that Gap4 is the functional orthologue of Sam3, the only -adenosylmethionine (SAM) transporter in , and we report that Gap4 is required for SAM-induced morphogenesis. is a commensal organism that can thrive in many niches in its human host. The environmental conditions at these different niches differ quite a bit, and this fungus must be able to sense these changes and adapt its metabolism to them. Apart from glucose and other sugars, the uptake of amino acids is very important. This is underscored by the fact that the genome encodes 6 orthologues of the general amino acid permease Gap1 and many other amino acid transporters. In this work, we characterize these six permeases and we show that Gap2 is the functional orthologue of Gap1 and that Gap4 is an orthologue of Sam3, an -adenosylmethionine (SAM) transporter. Furthermore, we show that Gap4 is required for SAM-induced morphogenesis, an important virulence factor of .