Matsuoka K, Taoka M, Satozawa N, Nakayama H, Ichimura T, Takahashi N, Yamakuni T, Song S Y, Isobe T
Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Japan.
Proc Natl Acad Sci U S A. 1994 Oct 11;91(21):9670-4. doi: 10.1073/pnas.91.21.9670.
A nuclear protein, termed leucine-rich acidic nuclear protein (LANP), has been isolated from among rat cerebellar proteins whose expression was transiently increased during an early stage of postnatal development. The amino acid sequence, deduced from its cDNA, showed that LANP contains 247 amino acids consisting of two distinct structural domains: the N-terminal domain characterized by "leucine-rich repeat," which is found in many eukaryotic proteins and which potentially functions in mediating protein-protein interactions, and the C-terminal domain characterized by a cluster of acidic amino acids with a putative nuclear localization signal. Immunohistochemical study using an antibody against LANP revealed that the protein is localized mainly in nuclei of Purkinje cells. In the rat cerebellum on postnatal day 7, LANP mRNA was expressed moderately in the external granule and Purkinje cells and weakly in the internal granule cells. The expression in these cells, especially in Purkinje cells, increased in the second postnatal week and thereafter decreased to an adult level. The structural characteristics, localization, and the stage- and cell type-specific expression suggest a potential role of LANP in a signal transduction pathway that directs differentiation of cerebellar neurons.
一种名为富含亮氨酸的酸性核蛋白（LANP）的核蛋白，是从小鼠小脑蛋白中分离出来的，其表达在出生后发育的早期阶段短暂增加。从其cDNA推导的氨基酸序列表明，LANP含有247个氨基酸，由两个不同的结构域组成：N端结构域的特征是“富含亮氨酸重复序列”，这在许多真核蛋白质中都有发现，可能在介导蛋白质-蛋白质相互作用中发挥作用；C端结构域的特征是一簇带有假定核定位信号的酸性氨基酸。使用抗LANP抗体的免疫组织化学研究表明，该蛋白主要定位于浦肯野细胞的细胞核中。在出生后第7天的大鼠小脑中，LANP mRNA在外部颗粒细胞和浦肯野细胞中适度表达，在内部颗粒细胞中微弱表达。这些细胞中的表达，尤其是浦肯野细胞中的表达，在出生后第二周增加，此后下降至成年水平。其结构特征、定位以及阶段和细胞类型特异性表达表明，LANP在指导小脑神经元分化的信号转导途径中可能发挥作用。
