Figure 1.

Epitope-tagged VZG-1 is expressed and functionally increases [³H]-LPA binding in plasma membranes of RH7777 hepatoma expressing no vzg-1. (A) Cytoplasmic RNAs (20 μg) from RH7777 hepatoma or B103 neuroblastoma cell line serum-starved for 24 h were subjected to Northern blot analysis (24) along with vzg-1 containing RNAs from brain and TSM, a cortical neuroblast cell line. Loading control, 28S RNA. (B) [³H]-LPA binding in plasma membranes of RH7777 cells transiently transfected with pflag or pflag/vzg-1. Specific binding in pflag/vzg-1-transfected cells was 6.4 ± 0.9 cpm/μg protein, 60% of total binding. Data are the mean ± SEM (n = 3). ∗, P < 0.05 (using Student’s t test) vs. pflag-transfected cells. (Inset) Immunoprecipitation with anti-flag antibody after [³⁵S]-methionine/cysteine labeling of pflag or pflag/vzg-1-transfected cells reveals a protein band of predicted size only in pflag/vzg-1-transfected cells.