Exploration of the DNA-recognition site for anti-DNA antibody inducing DNA-binding protein nucleobindin

我们在核结合的生理活性和优良特性的研究方面取得了以下进展。即使在没有自身免疫性疾病遗传背景的正常BALB/c小鼠中，给予重组核结合素也能诱导产生自身抗体，如抗DNA抗体。在狼疮易感系小鼠的淋巴器官，如MRL/LPR、C3H/GLD和雄性BXSB中，核结合蛋白mRNA的表达增强。通过使用针对核结合素肽产生的抗体进行免疫组织化学染色，也在蛋白水平上证明了狼疮易感小鼠核结合素合成的增强。抗人核结合素单抗在人恶性淋巴瘤细胞系Molt-4.5的核提取液中成功地免疫沉淀天然核结合素。从合成的含26个碱基长的随机序列的寡核苷酸中筛选出与人核结合蛋白具有高结合亲和力的寡核苷酸。在所选的寡核苷酸中反复发现一些基序。此外，在IL-2基因的上游区域还发现了CCACCACAATA和GTGTGGA等基序。核结合蛋白如何参与基因转录调控仍是个未知数。

We have achieved the following progresses in the studies on physiological activity and fine characteristics of nucleobindin.1. Administration of recombinant nucleobindin induced production of autoantibodies such as anti-DNA antibody even in normal BALB/c mice that have no genetical background of autoimmune disorders.2. Enhanced expression of nucleobindin mRNA was observed in the lymphoid organs of lupus-prone strains of mice such as MRL/lpr, C3H/gld, and male BXSB.3. Enhanced synthesis of nucleobindin in lupus-prone mice was demonstrated also in the protein level by immunohistochemical staining using an antibody produced against neclebindin peptide.4. A monoclonal antibody to human nucleobindin successfully immunoprecipitated native nucleobindin in the nuclear extract of human malignant lymphoma cell line Molt-4.5. The oligonucleotides which showed high binding affinity to human nucleobindin were selected from synthesized oligonucleotides containig 26-base-long random sequences. Some motif were repeatedly found in the selected oligonucleotides. Furthermore, such motif as CCACCACAATA and GTGTGGA were found in the up-stream region of IL-2 gene. It remains elusive how nucleobindin is involved in regulation of gene transcription.