Member of the two-component regulatory system HptS/HptR that regulates genes involved in hexose phosphate transport system in response to changes in extracellular phosphate sources (PubMed:25644013). Activates uhpT expression to facilitate glucose-6-phosphate/G6P utilization by directly binding to its promoter (PubMed:26711125). Antagonizes CcpA-dependent transcription of a subset of CcpA-regulated genes involved in antibiotic susceptibility (PubMed:30540769). Phosphorylated by HptS. Deletion leads to impaired growth when the available carbon source is limited to glucose-6-phosphate (PubMed:25644013). Deletion alters also antibiotic susceptibility (PubMed:30540769).