Table 1. LPP activity in cell lysates and immunoprecipitate from HBEpCs.

HBEpCs (∼70% confluence in 60 mm dishes) were infected with vector, Myc-tagged mLPP-1 wt, or Myc-tagged mLPP-1 (R217K) mutant adenoviral constructs (MOI 10; 1× 10⁶ cells per dish) for 24 h. Cell lysates were prepared as described in the Experimental section and aliquots of 500 μg of protein were subjected to immunoprecipitation overnight with anti-Myc antibody (1 μl per 500 μg of protein). For dephosphorylation of [³H]LPA, total cell lysates or immunoprecipitates from cells transfected with vector, wt or mutant LPP-1 were incubated with 1 μM [³H]LPA (specific radioactivity 2.2×10³ d.p.m./pmol) complexed with 0.1% BSA for 30 min at 37 °C. Lipids were extracted under acidic conditions and dephosphorylation of [³H]LPA to [³H]MOG was quantified by separation of lipids on TLC using hexane/diethyl ether/acetic acid (60:40;1, by vol.) as the developing solvent system. Results are expressed as % [³H]MOG formed from total [³H]LPA added for dephosphorylation.

	[3H]MOG formed (%)
	Vector	mLPP-1 wt–Myc	mLPP-1 mutant–Myc
Cell lysate	2.8	16.0	2.4
Immunoprecipitate	−	27.3	1.4