Table 1.

Relative Activities of Arabidopsis PI4P 5-Kinase Isoforms Expressed in Roots

SubstratePtdIns4P/PtdIns3P
ProteinPtdIns3PPtdIns4PPtdIns5PActivity Ratio
MBP2 ± 0.34 ± 0
PIP5K15 ± 0.8205 ± 1741.0
PIP5K252 ± 81206 ± 15623.0
PIP5K3178 ± 271972 ± 6611.0
PIP5K72 ± 0.337 ± 618.5
PIP5K83 ± 0.527 ± 39.0
PIP5K94 ± 0.6142 ± 2335.5
  • Catalytic activities were tested in vitro against different phosphatidylinositol-monophosphate substrates and indicate the rate of product formation in fmol min−1. Recombinant protein concentrations were balanced according to protein gel blot analysis. Data are the means of two independent experiments ± sd.