Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, 50 Flemington Road, Parkville, Victoria, 3052, Australia.
Department of Paediatrics, The University of Melbourne, 30 Royal Parade, Parkville, Victoria, 3052, Australia.
Mol Brain. 2020 Mar 30;13(1):52. doi: 10.1186/s13041-020-00584-7.
Pathogenic variants in the gene encoding the small GTPase Ras analogue in Brain 39b (RAB39B) are associated with early-onset parkinsonism. In this study we investigated the expression and localization of RAB39B (RNA and protein) in mouse brain tissue to gain a better understanding of its normal physiological function(s) and role in disease.We developed novel resources, including monoclonal antibodies directed against RAB39B and mice with Rab39b knockout, and performed real-time PCR and western blot analysis on whole brain lysates. To determine the spatial localization of Rab39b RNA and protein, we performed in-situ hybridization and immunohistochemistry on fresh frozen and fixed brain tissue. Our results show that RAB39B is localized throughout the cortex, hippocampus and substantia nigra of mice throughout postnatal life. We found high levels of RAB39B within MAP2 positive cortical and hippocampal neurons, and TH positive dopaminergic neurons in the substantia nigra pars compacta.Our studies support and extend current knowledge of the localization of RAB39B. We validate RAB39B as a neuron-enriched protein and demonstrate that it is present throughout the mouse cortex and hippocampus. Further, we observe high levels in the substantia nigra pars compacta, the brain region most affected in Parkinson's disease pathology. The distribution of Rab39b is consistent with human disease associations with parkinsonism and cognitive impairment. We also describe and validate novel resources, including monoclonal antibodies directed against RAB39B and mice with Rab39b knockout, both of which are valuable tools for future studies of the molecular function of RAB39B.
编码小 GTP 酶 Ras 模拟物在脑 39b（RAB39B）中的基因的致病变体与早发性帕金森病有关。在这项研究中，我们研究了 RAB39B（RNA 和蛋白质）在小鼠脑组织中的表达和定位，以更好地了解其正常生理功能及其在疾病中的作用。我们开发了新的资源，包括针对 RAB39B 的单克隆抗体和 Rab39b 敲除小鼠，并对全脑裂解物进行了实时 PCR 和 Western blot 分析。为了确定 Rab39b RNA 和蛋白质的空间定位，我们对新鲜冷冻和固定的脑组织进行了原位杂交和免疫组织化学分析。我们的结果表明，RAB39B 在整个出生后生命过程中定位于小鼠的皮质、海马体和黑质。我们发现，在 MAP2 阳性皮质和海马神经元以及黑质致密部的 TH 阳性多巴胺能神经元中，RAB39B 的水平很高。我们的研究支持并扩展了 RAB39B 定位的现有知识。我们验证了 RAB39B 是一种富含神经元的蛋白质，并证明它存在于整个小鼠皮质和海马体中。此外，我们在黑质致密部观察到高水平，黑质致密部是帕金森病病理学中受影响最严重的大脑区域。Rab39b 的分布与帕金森病和认知障碍的人类疾病关联一致。我们还描述并验证了新的资源，包括针对 RAB39B 的单克隆抗体和 Rab39b 敲除小鼠，它们都是未来研究 RAB39B 分子功能的有价值的工具。
