PP2A activity measured using a phosphoserine substrate in Arl2 variant lines.

Values represent the picomoles of phosphate issued after the dephosphorylation of the above substrates and are denoted as mean ± standard deviation.各组数值代表上述底物经去磷酸化反应后释放的磷酸盐的皮摩尔（picomoles）数，结果以平均值±标准差的形式表示。