Low-affinity phosphate transporter; acts upstream of Pho81p in regulation of the PHO pathway; deletion of
pho84,
pho87,
pho89,
pho90, and
pho91 causes synthetic lethality; transcription independent of Pi and Pho4p activity; overexpression results in vigorous growth; PHO90 has a paralog, PHO87, that arose from the whole genome duplication