Loss Omar, Stephenson F Anne
School of Pharmacy, University College London, London, United Kingdom.
J Neurosci Res. 2015 Jul;93(7):1056-66. doi: 10.1002/jnr.23549. Epub 2015 Feb 4.
Neuronal function requires regulated anterograde and retrograde trafficking of mitochondria along microtubules by using the molecular motors kinesin and dynein. Previous work has established that trafficking kinesin proteins (TRAKs),TRAK1 and TRAK2, are kinesin adaptor proteins that link mitochondria to kinesin motor proteins via an acceptor protein in the mitochondrial outer membrane, etc. the Rho GTPase Miro. Recent studies have shown that TRAK1 preferentially controls mitochondrial transport in axons of hippocampal neurons by virtue of its binding to both kinesin and dynein motor proteins, whereas TRAK2 controls mitochondrial transport in dendrites resulting from its binding to dynein. This study further investigates the subcellular localization of TRAK1 and TRAK2 in primary cultures of hippocampal and cortical neurons by using both commercial antibodies and anti-TRAK1 and anti-TRAK2 antibodies raised in our own laboratory (in-house). Whereas TRAK1 was prevalently localized in axons of hippocampal and cortical neurons, TRAK2 was more prevalent in dendrites of hippocampal neurons. In cortical neurons, TRAK2 was equally distributed between axons and dendrites. Some qualitative differences were observed between commercial and in-house-generated antibody immunostaining.
神经元功能需要通过分子马达驱动蛋白驱动蛋白和动力蛋白,沿着微管对线粒体进行有序的顺行和逆行运输。先前的研究已经证实,运输驱动蛋白(TRAKs),即TRAK1和TRAK2,是驱动蛋白衔接蛋白,它们通过线粒体外膜中的一种受体蛋白(如Rho GTP酶Miro),将线粒体与驱动蛋白连接起来。最近的研究表明,TRAK1由于其与驱动蛋白和动力蛋白的结合,优先控制海马神经元轴突中的线粒体运输,而TRAK2则通过其与动力蛋白的结合来控制树突中的线粒体运输。本研究通过使用商业抗体以及我们自己实验室制备的抗TRAK1和抗TRAK2抗体(自制抗体),进一步研究了TRAK1和TRAK2在海马和皮质神经元原代培养物中的亚细胞定位。TRAK1主要定位于海马和皮质神经元的轴突中,而TRAK2在海马神经元的树突中更为常见。在皮质神经元中,TRAK2在轴突和树突中分布均匀。在商业抗体和自制抗体免疫染色之间观察到了一些定性差异。