Wijkander J, Sundler R
Department of Medical and Physiological Chemistry, Lund University, Sweden.
FEBS Lett. 1992 Oct 26;311(3):299-301. doi: 10.1016/0014-5793(92)81124-5.
Stimulation of 32P-labeled macrophages with phorbol ester caused an increase in phosphorylation of the intracellular, high molecular weight phospholipase A2. This increase in phosphorylation was accompanied by an increase in enzyme activity, but led to no detectable shift in the concentration dependence for Ca(2+)-induced activation. The phosphorylated phospholipase A2 could be dephosphorylated by treatment with acid phosphatase, and such treatment also reduced its catalytic activity. Together with previous data, these results indicate that the arachidonate-mobilizing phospholipase A2 is dually regulated by Ca2+ (membrane interaction) and by phosphorylation (catalytic activity).
用佛波酯刺激32P标记的巨噬细胞会导致细胞内高分子量磷脂酶A2的磷酸化增加。这种磷酸化的增加伴随着酶活性的增加，但在Ca(2+)诱导激活的浓度依赖性方面未检测到明显变化。磷酸化的磷脂酶A2可用酸性磷酸酶处理使其去磷酸化，这种处理也会降低其催化活性。结合先前的数据，这些结果表明，花生四烯酸动员磷脂酶A2受Ca2+(膜相互作用)和磷酸化(催化活性)双重调节。
