Human PHOSPHO1 exhibits high specific phosphoethanolamine and phosphocholine phosphatase activities

SJ Roberts, Alan James Stewart, PJ Sadler, C Farquharson

Research output: Contribution to journalArticlepeer-review

103 Citations (Scopus)

Abstract

Human PHOSPHO1 is a phosphatase enzyme for which expression is upregulated in mineralizing cells. This enzyme has been implicated in the generation of Pi for matrix mineralization, a process central to skeletal development. PHOSPHO1 is a member of the haloacid dehalogenase (HAD) superfamily of Mg2+-dependent hydrolases. However, substrates for PHOSPHO1 are, as yet, unidentified and little is known about its activity. We show here that PHOSPHO1 exhibits high specific activities toward phosphoethanolamine (PEA) and phosphocholine (PCho). Optimal enzymic activity was observed at approx. pH 6.7. The enzyme shows a high specific Mg2+-dependence, with apparent Km values of 3.0 µM for PEA and 11.4 µM for PCho. These results provide a novel mechanism for the generation of Pi in mineralizing cells from PEA and PCho.
Original languageEnglish
Pages (from-to)59-65
Number of pages7
JournalBiochemical Journal
Volume382
Issue number1
DOIs
Publication statusPublished - 15 Aug 2004

Keywords

  • Bone
  • Haloacid Dehalogenase (HAD) superfamily
  • Mineralization
  • PHOSPHO1
  • Phosphocholine (PCho)

Fingerprint

Dive into the research topics of 'Human PHOSPHO1 exhibits high specific phosphoethanolamine and phosphocholine phosphatase activities'. Together they form a unique fingerprint.

Cite this