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. Activates uhpT expression to facilitate glucose-6-phosphate/G6P utilization by directly binding to its promoter. Antagonizes CcpA-dependent transcription of a subset of CcpA-regulated genes involved in antibiotic susceptibility. Phosphorylated by HptS.