Regulatgion of translation by protein phosphorylation.

通过蛋白质磷酸化调节翻译。

基本信息

批准号：
12680623
负责人：
SHIMA Hiroshi
金额：
$ 2.69万
依托单位：
HOKKAIDO UNIVERSITY
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 2001
项目状态：
已结题

项目摘要

1. Regulation of translation by type 1 protein phosphatase (PP1 )PP1 is thought to be involved in dephosphorylation and negative regulation of S6 protein. Two kinds of PP1 regulatory proteins (NIPP-1 and 1-4) were identified and characterized. NIPP-1 was shown to bind 4 kinds of PP1 catalytic subunits with similar affinity. Expression of NIPP-1 mRNA in rat hepatomas was analyzed and It was shown that its level was positively correlated with the malignant phenotype.We have isolated a novel and the most potent PP1 inhibitory protein named as I-4. IC50 towards PP1 of is 0.2hM. The experiments based on deletion mutants showed that I-4 inhibits PP1 by covering catalytic site of PP1 catalytic subunit by binding with 3 domains.2. S6 kinase deficient mouseBased on the phenotype of S6 kinase deficient mouse, we reveled a novel isotope of S6K, S6K2. Development and analysis of S6K2 deficient mouse is currently, on going.3. Regulation of translation by type 2A protein phosphatase (PP2A)APP2A regulatory protein (I-2/PP2A) was isolated. The expression of I-2/PP2A mRNA was regulated up regulated at G1/S. Over-expression of I-2/PP2A suppressed the cell proliferation.4. Mechanism of immunosuppressive drugAlthough the target of immunosuppressive drug such as cyclosporinA and FK506 is identified as calcineurin, the assay method for calcineurin activity has not been established well. We established the efficient and accurate method for enzyme activity of calcineurin.5. Cross-talk between translation and major signal cascadesWe have identified novel negative regulator named as MKP-7 (for MAPK pathway) and PTP epsilon (for JAK-STAT) and cauterized the mode of action of these proteins.

1. 1型蛋白磷酸酶(PP1)对翻译的调节 PP1被认为参与S6蛋白的去磷酸化和负调节。鉴定并表征了两种 PP1 调节蛋白（NIPP-1 和 1-4）。 NIPP-1 显示以相似的亲和力结合 4 种 PP1 催化亚基。对大鼠肝癌中NIPP-1 mRNA的表达进行分析，发现其水平与恶性表型呈正相关。我们分离出一种新型且最强效的PP1抑制蛋白，命名为I-4。对 PP1 的 IC50 为 0.2hM。基于缺失突变体的实验表明，I-4通过与3个结构域结合覆盖PP1催化亚基的催化位点来抑制PP1。2． S6激酶缺陷小鼠基于S6激酶缺陷小鼠的表型，我们发现了S6K的新同位素S6K2。目前正在进行S6K2缺陷型小鼠的开发和分析。3．分离了 2A 型蛋白磷酸酶 (PP2A)APP2A 调节蛋白 (I-2/PP2A) 对翻译的调节。 I-2/PP2A mRNA的表达在G1/S时上调。 I-2/PP2A过表达抑制细胞增殖。 4．免疫抑制剂的作用机制虽然环孢素A、FK506等免疫抑制剂的作用靶点被确定为钙调磷酸酶，但钙调磷酸酶活性的测定方法尚未建立。建立了高效、准确的钙调神经磷酸酶酶活测定方法。 5．翻译和主要信号级联之间的串扰我们已经确定了名为 MKP-7（针对 MAPK 途径）和 PTP epsilon（针对 JAK-STAT）的新型负调节因子，并烧灼了这些蛋白质的作用模式。