Chen Jun-Song, Exton John H
Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
Biochem Biophys Res Commun. 2005 Aug 12;333(4):1322-6. doi: 10.1016/j.bbrc.2005.06.048.
The phosphorylation sites in phospholipase D2 (PLD2) induced by activation of protein kinase Calpha (PKCalpha) in COS 7 cells were analyzed by mass spectrometry. Ser134, 146, and 243, and Thr72, 99/100, and 252 were identified. These sites were mutated to Ala and the double mutation of Ser243 and Thr252 eliminated the phosphorylation. However, the PLD2 activity, and the binding between PKCalpha and PLD2 were unaffected by the mutations. We conclude that phosphorylation of these residues is not required for PLD2 activation by PKCalpha, and that protein-protein interaction between PLD2 and PKCalpha is sufficient to activate PLD2.
通过质谱分析了蛋白激酶Cα（PKCα）激活COS 7细胞中磷脂酶D2（PLD2）所诱导的磷酸化位点。鉴定出了丝氨酸134、146和243以及苏氨酸72、99/100和252。这些位点被突变为丙氨酸，丝氨酸243和苏氨酸252的双突变消除了磷酸化。然而，PLD2活性以及PKCα与PLD2之间的结合不受这些突变的影响。我们得出结论，PKCα激活PLD2不需要这些残基的磷酸化，并且PLD2与PKCα之间的蛋白质-蛋白质相互作用足以激活PLD2。
