Related Experiment Video
Updated: Aug 24, 2026

In Vitro Assay to Measure Phosphatidylethanolamine Methyltransferase Activity
Published on: January 5, 2016
Human PHOSPHO1 exhibits high specific phosphoethanolamine and phosphocholine phosphatase activities
Scott J Roberts1, Alan J Stewart, Peter J Sadler
1Roslin Institute, Roslin, Midlothian EH25 9PS, U.K.
Abstract:
Human PHOSPHO1 is a phosphatase enzyme for which expression is upregulated in mineralizing cells. This enzyme has been implicated in the generation of P(i) 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 K(m) values of 3.0 microM for PEA and 11.4 microM for PCho. These results provide a novel mechanism for the generation of P(i) in mineralizing cells from PEA and PCho.
More Related Videos
Related Concept Videos
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Phosphorylation
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...

