Protein Kinase D Controls the Integrity of Golgi Apparatus and the Maintenance of Dendritic Arborization in Hippocampal Neurons
Protein Kinase D Controls the Integrity of Golgi Apparatus and the Maintenance of Dendritic Arborization in Hippocampal Neurons
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DOI：
10.1091/mbc.e08-09-0957
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发表时间：
2009-04-01
影响因子：
3.3
通讯作者：
Schlett, Katalin
中科院分区：
文献类型：
--
作者：
Czoendoer, Katalin;Ellwanger, Kornelia;Schlett, Katalin
蛋白激酶D（PKD）参与多种细胞功能，包括高尔基体分泌囊泡分裂和质膜定向运输。在这里，我们报告PKD在海马神经元的表达和功能。增强的绿色荧光蛋白（EGFP）标记的PKD活性报告在小鼠胚胎海马神经元的表达揭示了高内源性PKD活性在高尔基复合体和树突，而PKD活性被排除在轴突与轴突成熟平行。荧光标记的野生型PKD 1和组成型活性PKD 1（S738/742 E）（caPKD 1）在神经元中的表达显示，这两种蛋白质在trans-Golgi网络（TGN）中略有富集，并且不干扰其线状形态。相比之下，显性负性激酶失活PKD 1（K612 W）（kdPKD 1）的表达导致神经元高尔基复合体的破坏，kdPKD 1强烈定位于TGN片段。从具有可诱导的神经元特异性表达kdPKD 1-EGFP的转基因小鼠中获得了类似的发现。作为一个突出的后果kdPKD 1的表达，转染的神经元的树突树减少，而caPKD 1增加树突状分支。因此，我们的研究结果提供了直接的证据，PKD活性是选择性地参与维持树突状分支和高尔基体结构的海马神经元。
Protein kinase D (PKD) is known to participate in various cellular functions, including secretory vesicle fission from the Golgi and plasma membrane-directed transport. Here, we report on expression and function of PKD in hippocampal neurons. Expression of an enhanced green fluorescent protein (EGFP)-tagged PKD activity reporter in mouse embryonal hippocampal neurons revealed high endogenous PKD activity at the Golgi complex and in the dendrites, whereas PKD activity was excluded from the axon in parallel with axonal maturation. Expression of fluorescently tagged wild-type PKD1 and constitutively active PKD1(S738/742E) (caPKD1) in neurons revealed that both proteins were slightly enriched at the trans-Golgi network (TGN) and did not interfere with its thread-like morphology. By contrast, expression of dominant-negative kinase inactive PKD1(K612W) (kdPKD1) led to the disruption of the neuronal Golgi complex, with kdPKD1 strongly localized to the TGN fragments. Similar findings were obtained from transgenic mice with inducible, neuron-specific expression of kdPKD1-EGFP. As a prominent consequence of kdPKD1 expression, the dendritic tree of transfected neurons was reduced, whereas caPKD1 increased dendritic arborization. Our results thus provide direct evidence that PKD activity is selectively involved in the maintenance of dendritic arborization and Golgi structure of hippocampal neurons.