PHOSPHORYLATION OF RABPHILIN-3A BY CA2+/CALMODULIN-DEPENDENT AND CAMP-DEPENDENT PROTEIN-KINASES IN-VITRO
PHOSPHORYLATION OF RABPHILIN-3A BY CA2+/CALMODULIN-DEPENDENT AND CAMP-DEPENDENT PROTEIN-KINASES IN-VITRO
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DOI：
10.1523/jneurosci.15-03-02385.1995
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发表时间：
1995-03-01
影响因子：
5.3
通讯作者：
SUDHOF, TC
中科院分区：
文献类型：
--
作者：
FYKSE, EM;LI, C;SUDHOF, TC
神经递质释放的调节被认为涉及蛋白质磷酸化对释放概率的调节。为了确定新的目标，这样的监管过程中，我们研究了rabphilin-3A的磷酸化在体外。Rabphilin-3A是一种突触囊泡蛋白，以GTP依赖性方式与rab 3A相互作用，并以磷脂依赖性方式结合Ca 2+。在这里，我们表明，rabphilin-3A是一个有效的底物的Ca 2 +/钙调素依赖性蛋白激酶II，磷酸化大鼠rabphilin-3A在残基234和274，和cAMP依赖性蛋白激酶，磷酸化大鼠rabphilin-3A在残基234。这确定了rabphilin-3A的中间区域位于N-末端rab 3A-结合序列和C-末端C-2-结构域之间，参与Ca 2 +/磷脂结合作为调节结构域。因此，rabphilin-3A是突触囊泡上的第二磷蛋白，其类似于突触蛋白I，可以整合来自细胞中多个蛋白激酶信号传导途径的磷酸化信号。
Regulation of neurotransmitter release is thought to involve modulation of the release probability by protein; phosphorylation. In order to identify novel targets for such regulatory processes, we have studied the phosphorylation of rabphilin-3A in vitro. Rabphilin-3A is a synaptic vesicle protein that interacts with rab3A in a GTP-dependent manner and binds Ca2+ in a phospholipid-dependent manner. Here we show that rabphilin-3A is an efficient substrate for Ca2+/calmodulin-dependent protein kinase II, which phosphorylates rat rabphilin-3A at residue 234 and 274, and for cAMP-dependent protein kinase, which phosphorylates rat rabphilin-3A at residue 234. This identifies the middle region of rabphilin-3A situated between the N-terminal rab3A-binding sequences and the C-terminal C-2-domains involved in Ca2+/phospholipid binding as a regulatory domain. Thus, rabphilin-3A is a second phosphoprotein on synaptic vesicles that, similar to synapsin I, may integrate phosphorylation signals from multiple protein kinase signaling pathways in the cell.