Molecular mechanism of signal transduction mediated by Rel/NFkB

Rel/NFkB介导的信号转导分子机制

• 批准号: 05454642
• 负责人: INOUE Jun-ichiro
• 金额: $ 3.71万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05454642/
• 关键词: Transcription factor; Rel; NFkappaB; Signal transduction; Molecular biology; NFkB; 蛋白質間相互作用

1. Molecular Mechanism of Rel/NFkappaB activationActivation of Rel/NFkappaB is achieved by the signal-induced rapid phosphorylation and degradation of inhibitory protein IkappaBalpha. To explore the molecular mechanism of signal-induced depletion of IkappaBalpha, we have delineated the domain in IkappaBalpha that is required for the regulation. In contrast to the previous reports, the PEST-like sequences dispensable for TNFalpha-induced degradation whereas the six ankyrin repeats are required. However, neither ankyrin repeats nor carboxyl-terminal region including the PEST-like sequences are required for TNFalpha-induced phosphorylation.2. Signal transduction pathway emanating from membrane receptors to Rel/IkappaBalpha complexWe have found that signals emanating from CD40 link to Rel/NFkappaB activation. To identify molecules which transduce CD40 signalings, we have utilized the yeast two-hybrid system to clone cDNAs encoding proteins that bind the cytoplasmic tail of CD40, cDNAs encoding a putative signal transducer protein, designated TRAF5 and TRAF6, have been molecularly cloned. Overexpression of TRAF5 or TRAF6 activates transcription factor NFkappaB.Thus, we are looking for the down stream transducer of these proteins. Furthermore we have demonstrated that cupric ion blocks NFkappaB activation through inhibiting the signal-induced phosphorylation of IkappaBalpha Target molecule of cupric ion remain to be identified.3. Identification of novel kappaB proteinsTo identify novel IkappaB cDNAs, an expression cDNA library has been screened using p65 subunit of NFkappaB as a probe. This study is still in the progress.4. Chromosomal assignment of rel, NFkappaB and IkappaB genes in RatWe have indentified that NFKB-1 (p50, IkappaBgamma) in on the Rat chromosome #2. Assignment of rel and IkappaBalpha is still in the Progress.

1. Rel/NF κ B激活的分子机制Rel/NF κ B的激活是通过信号诱导的抑制蛋白IkappaB α的快速磷酸化和降解来实现的。为了探索信号诱导的IkappaB α耗竭的分子机制，我们描绘了IkappaB α中调控所需的结构域。与以前的报道相反，PEST样序列对TNF α诱导的降解起抑制作用，而六个锚蛋白重复序列是必需的。然而，锚蛋白重复序列和包括PEST样序列的羧基末端区域都不是TNFa诱导的磷酸化所必需的。从膜受体到Rel/NF κ B α复合物的信号转导途径我们已经发现，从CD 40发出的信号与Rel/NF κ B活化有关。为了鉴定阻断CD 40信号传导的分子，我们利用酵母双杂交系统克隆了编码结合CD 40胞质尾区的蛋白质的cDNA，编码推定的信号转导蛋白的cDNA，命名为TRAF 5和TRAF 6，已经被分子克隆。TRAF 5或TRAF 6的过表达激活转录因子NF κ B，因此，我们正在寻找这些蛋白质的下游转导子。此外，我们已经证明铜离子通过抑制信号诱导的IkappaB α磷酸化来阻断NF κ B的活化，铜离子的靶分子仍有待鉴定.为了鉴定新的IkappaB cDNA，使用NF κ B的p65亚基作为探针筛选表达cDNA文库。这项研究仍在进行中。Rel、NF κ B和IkappaB基因的染色体定位我们已经鉴定出NF κ B-1（p50，IkappaB γ）位于大鼠2号染色体上。rel和IkappaBalpha的分配仍在进行中。

项目成果

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Suzuki,K.：“编码哺乳动物 RelB 爪蟾同源物的 cDNA 的分子克隆。”

Ishida,T.: "CD40signaling-mediated induction of Bcl-xL,Cdk4 and Cdk6 : Implication of their co-operation in selective B cell growth." J.Immunol.155. 5527-5535 (1995)

Ishida,T.：“CD40 信号介导的 Bcl-xL、Cdk4 和 Cdk6 诱导：它们在选择性 B 细胞生长中合作的意义。”

Otuka, M., Fujita, M., Aoki, T., Sugiura, Y., Ishii, S., Yamamoto, T., and Inoue, J.: "Novel zinc chelators which inhibit the binding of HIV-EP1 (HIV enhancer binding protein) to NFkappaB recognition sequence" J.Med.Chem. 37. 4267-4269 (1994)

Otuka, M.、Fujita, M.、Aoki, T.、Sugiura, Y.、Ishii, S.、Yamamoto, T. 和 Inoue, J.：“抑制 HIV-EP1（HIV-EP1）结合的新型锌螯合剂

Hirai,H.: "Tax protein of human T cell leukemia virus type 1(HTL V-1)binds to the ankyrin motifs of IkB and induces nuclear translocation of NFkB proteins for transcriptional activation" Proc.Natl.Acad.Sci.USA. 91. 3584-3588 (1994)

Hirai,H.：“人 T 细胞白血病病毒 1 型 (HTL V-1) 的 Tax 蛋白与 IkB 的锚蛋白基序结合，并诱导 NFkB 蛋白的核转位以实现转录激活”Proc.Natl.Acad.Sci.USA。

Ishida, T., Kobayashi, N., Tojo, T., Ishida, S., Yamamoto, T.and Inoue, J.: "CD40 signaling-mediated induction of Bcl-xL,Cdk4 and Cdk6 : Implication of their co-operation in selective B cell growth" J.Immunol.155. 5527-5535 (1995)

Ishida, T.、Kobayashi, N.、Tojo, T.、Ishida, S.、Yamamoto, T. 和 Inoue, J.：“CD40 信号介导的 Bcl-xL、Cdk4 和 Cdk6 诱导：它们的共同作用的含义