Choi Dong-Kug, Yoo Kyeong-Won, Hong Sung-Kook, Rhee Myungchull, Sakaki Yoshiyuki, Kim Cheol-Hee
Department of Neurology and Neuroscience, Cornell University, New York, NY 10021, USA.
Biochem Biophys Res Commun. 2003 Jun 6;305(3):448-54. doi: 10.1016/s0006-291x(03)00789-7.
The human neuroblastoma apoptosis-related RNA-binding protein NAPOR is an ELAV-like RNA-binding protein with three characteristic RNA recognition motifs (RRMs). We report here the cloning and characterization of a zebrafish Napor that has a high sequence homology to human NAPOR protein. Whole-mount in situ hybridization analysis revealed that zebrafish napor is dynamically expressed in early development. In addition to its maternal expression, napor transcripts were detected in adaxial mesoderm cells and lateral neural plate cells at early somite stages. By 10-somite stage, napor expression was restricted to the central nervous system, having a specific expression domain of rhombomere 5 in the hindbrain. In 24 hpf embryo, napor was expressed in subsets of differentiating neural cells in the forebrain and hindbrain as well as somitic muscle cells. The number of napor-expressing neural cells was greatly increased in the mind bomb mutant that has neurogenic phenotype resulting from deficits in the Notch signaling pathway. Furthermore, overexpression of napor by RNA microinjection resulted in severe defects in nervous system and gastrulation, suggesting the need for tight control of napor gene regulation during embryo development.
人类神经母细胞瘤凋亡相关RNA结合蛋白NAPOR是一种具有三个特征性RNA识别基序（RRMs）的ELAV样RNA结合蛋白。我们在此报告斑马鱼Napor的克隆和特征，其与人类NAPOR蛋白具有高度的序列同源性。整体原位杂交分析显示，斑马鱼napor在早期发育中动态表达。除了母源表达外，在早期体节阶段，在近轴中胚层细胞和外侧神经板细胞中检测到napor转录本。到10体节阶段时，napor表达局限于中枢神经系统，在后脑的菱脑节5中有特定的表达域。在受精后24小时的胚胎中，napor在前脑和后脑以及体节肌细胞中的部分分化神经细胞中表达。在mind bomb突变体中，表达napor的神经细胞数量大大增加，该突变体具有因Notch信号通路缺陷导致的神经源性表型。此外，通过RNA显微注射过表达napor会导致神经系统和原肠胚形成严重缺陷，这表明在胚胎发育过程中需要严格控制napor基因的调控。
