Depletion of 43-kD growth-associated protein in primary sensory neurons leads to diminished formation and spreading of growth cones.
Depletion of 43-kD growth-associated protein in primary sensory neurons leads to diminished formation and spreading of growth cones.
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DOI：
10.1083/jcb.123.2.417
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发表时间：
1993-10
期刊：
影响因子：
--
通讯作者：
Caroni P
中科院分区：
文献类型：
--
作者：
Aigner L;Caroni P
43 kD的生长相关蛋白（GAP-43）是生长轴突、发育神经末梢和神经胶质细胞的主要蛋白激酶C（PKC）底物。它是一种与皮质细胞骨架和膜相关的高度亲水性蛋白质。在神经元中，它从细胞体迅速转运到生长锥和神经末梢，并在那里积累。为了确定GAP-43在轴突生长中的作用，我们分析了培养的背根神经节（DRG）神经元中的轴突再生，这些神经元已经用三种非重叠反义寡核苷酸中的任何一种耗尽了GAP-43。差距-43耗竭程序对该蛋白质具有特异性，并且相关PKC底物MARCKS的反义寡核苷酸对GAP-43免疫反应性没有可检测的影响。我们报告说，神经突起的生长和形态依赖于GAP-43在神经元中的底物特异性的方式的水平。当生长在层粘连蛋白基质上时，GAP-43缺失的神经元比表达GAP-43的神经元延伸更长、更薄、分支更少的神经突，生长锥明显更小。相反，当DRG神经元铺在聚-L-鸟氨酸上时，GAP-43表达的抑制阻止了生长锥和神经突的形成。这些发现表明GAP-43在生长锥的形成和神经突起的生长中起重要作用。它可能参与增强生长锥对影响过程形成和指导的外部信号的反应。
The 43-kD growth-associated protein (GAP-43) is a major protein kinase C (PKC) substrate of growing axons, and of developing nerve terminals and glial cells. It is a highly hydrophilic protein associated with the cortical cytoskeleton and membranes. In neurons it is rapidly transported from the cell body to growth cones and nerve terminals, where it accumulates. To define the role of GAP-43 in neurite outgrowth, we analyzed neurite regeneration in cultured dorsal root ganglia (DRG) neurons that had been depleted of GAP-43 with any of three nonoverlapping antisense oligonucleotides. The GAP-43 depletion procedure was specific for this protein and an antisense oligonucleotide to the related PKC substrate MARCKS did not detectably affect GAP-43 immunoreactivity. We report that neurite outgrowth and morphology depended on the levels of GAP-43 in the neurons in a substrate-specific manner. When grown on a laminin substratum, GAP-43- depleted neurons extended longer, thinner and less branched neurites with strikingly smaller growth cones than their GAP-43-expressing counterparts. In contrast, suppression of GAP-43 expression prevented growth cone and neurite formation when DRG neurons were plated on poly- L-ornithine. These findings indicate that GAP-43 plays an important role in growth cone formation and neurite outgrowth. It may be involved in the potentiation of growth cone responses to external signals affecting process formation and guidance.