Production of norbin (a novel neurite-outgrowth factor) deficient mouse

Norbin（一种新型神经突生长因子）缺陷型小鼠的生产

基本信息

批准号：
12640670
负责人：
MARUYAMA Kei
金额：
$ 2.24万
依托单位：
Saitama Medical School (2001-2002)Tokyo Metropolitan Organization for Medical Research (2000)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

Norbin is a novel gene, which is localized in central and peripheral neurons. Its expression is increased in rat hippocampus slices by the treatment of tetraethylammonium, which induces the facilitation of synaptic transmission as long term potentiation induced by tetanus stimulation. When norbin was overexpressed in Neuro2a cells, neural culture cell line, neurite outgrowth was observed. From these results it was suggested that norbin is related to neural plasticity. Norbin was reported by another group as neurochondrin. Secreted norbin was shown to promote hydroxyapatide resorptive activity of bone marrow cells. Norbin is secreted from COS cells overexpressing it. No signal peptide sequence is observed in that of norbin, and it was secreted as a whole molecule without any processing. The deletion of C-terminal of the middle portion of norbin reduced the secretion. This secretion was not inhibited by brefeldin A. The secretory mechanism is worth for the future study. We could not obtain the homologous recombinant ES cells to make a norbin-deficient mouse. The very low efficiency of the homologous recombination of the norbin gene might be because of the gene structure of norbin. The random insertion strategy performed by a German group produced a norbin deficient mouse by chance. However, the insertion was very near the C-terminal region and this C-terminal region deficient norbin was expressed as much as wild one. No structural or functional changes were observed in the mutant mice. It was concluded that this C-terminal portion of norbin had no significant physiological meanings. The completely deficient mice were necessary for the further study on the physiological function of norbin.

Norbin是一种新基因，位于中枢和外周神经元中。经过四乙铵处理后，其在大鼠海马切片中的表达增加，从而诱导突触传递的促进，如破伤风刺激诱导的长时程增强。当 Norbin 在 Neuro2a 细胞、神经培养细胞系中过表达时，观察到神经突生长。这些结果表明诺宾与神经可塑性有关。诺宾被另一组报告为神经软骨素。分泌的诺宾被证明可以促进骨髓细胞的羟基磷灰石再吸收活性。 Norbin 由过度表达它的 COS 细胞分泌。在norbin中没有观察到信号肽序列，并且它是作为整个分子分泌的，没有任何加工。 Norbin中部C末端的缺失减少了分泌。这种分泌不受布雷菲德菌素A的抑制。其分泌机制值得进一步研究。我们无法获得同源重组ES细胞来制备norbin缺陷型小鼠。 Norbin基因同源重组效率极低可能是由于norbin基因结构的原因。德国研究小组实施的随机插入策略偶然产生了诺宾缺陷小鼠。然而，插入非常靠近C端区域，并且该C端区域缺陷的norbin的表达与野生的一样多。在突变小鼠中没有观察到结构或功能变化。结论是norbin的这个C末端部分没有显着的生理意义。完全缺陷小鼠是进一步研究norbin生理功能所必需的。