ROLE OF TVI 1 IN APOPTOSIS

描述：(根据研究人员的摘要改编)TVL-1,269个氨基酸 Ankyrin Repeat蛋白是通过筛选小鼠T细胞双杂交而鉴定的 与Raf-1相关的蛋白质的cDNA文库。编码TVL-1的基因 定位于人类染色体19p12，MEF2B上游0.7kb，表达于 所有受测组织在造血和淋巴器官中的水平最高 睾丸。TVL-1蛋白定位于胞核和胞浆。 Raf-1/TVL-1关联负责双向交互， Raf-1磷酸化TVL-1和TVL-1增强EGF或 磷酸化诱导的Raf-1的激活。筛选互作交配 约500个TVL-1相互作用蛋白的文库显示 TVL-1还结合Mcl-1、Bclxl和Bad，以及细胞周期蛋白D1、D2和D3。 此外，TVL-1与另外两种蛋白质结合并被其磷酸化 激酶、Tpl-2和Akt。TVL-1和TPL-2也与APAF-1结合，并且 APAF-1相关的proaspase-9，但它们不结合proaspase-3。最近， 申请人表明，当TVL-1和TPL-2共同表达时，相互作用 增强与proaspase-9的相互作用。更有趣的是， 野生型而不是激酶死亡的TPL-2，TVL-1与原天冬氨酸蛋白酶-3结合 并将其与caspase-9并列。TPL-2介导的细胞并列 Proaspase-3与caspase-9的结合被Akt抑制。这些数据表明，TVL-1， 与TPL-2结合，促进APAF-1的组装/稳定性 而Akt要么干扰其组装，要么促进其 解离。与组装在一起的复合体相关的TVL-1和Proaspase-9 TVL-1和TPL-2结合的存在都是磷酸化的。AS 从前面的相互作用预测，依赖于caspase-9的caspase-3 TPL-2诱导永生化未转化细胞的激活和凋亡 经TVL-1处理后，TVL-1的诱导效果明显增强。TVL-1的异位表达也增强了 肿瘤坏死因子α诱导NIH3T3细胞caspase-3激活和凋亡。 其他人的独立研究表明，TVL-1(RFXANK)有助于 多分子转录复合体在X位上的组装/稳定性 第二类MHC推进剂。TVL-1基因的突变使这些启动子沉默， 它们负责补充裸露淋巴细胞的B组 综合症。以上数据的综合表明，TVL-1是一种 有助于细胞质和细胞质组装/稳定的适配蛋白 和核多分子复合体。此应用程序解决了以下角色 TVL-1在这种复合体的组装和功能中的作用。

DESCRIPTION: (Adapted from the investigator's abstract) Tvl-1, a 269 amino acid ankyrin repeat protein, was identified by screening a murine T-cell two hybrid cDNA library for proteins that associate with Raf-1. The gene encoding Tvl-1 maps to human chromosome 19p12, 0.7 kb upstream of MEF2B and is expressed in all tested tissues with highest levels in hematopoietic and lymphoid organs and testes. The Tvl-1 protein is localized in both the nucleus and the cytoplasm. The Raf-1/Tvl-1 association is responsible for a two-way interaction, with Raf-1 phosphorylating Tvl-1 and Tvl-1 enhancing the EGF or phosphorylation-induced activation of Raf-1. Screening an interaction mating library of approximately 500 proteins for Tvl-1 interactors, revealed that Tvl-1 also binds Mcl-1, Bcl-XL and Bad, as well as cyclins D1, D2 and D3. Moreover, Tvl-1 binds to and is phosphorylated by two additional protein kinases, Tpl-2 and Akt. Tvl-1 as well as Tpl-2 also binds Apaf-1, and the Apaf-1-associated procaspase-9, but they do not bind procaspase-3. Recently, the applicant showed that Tvl-1 and Tpl-2, when co-expressed, reciprocally enhance the interaction of each other with procaspase-9. More interesting, in the presence of wild type, but not kinase-dead Tpl-2, Tvl-1 binds procaspase-3 and juxtaposes it to caspase-9. The Tpl-2-mediated juxtaposition of procaspase-3 with caspase-9 is inhibited by Akt. These data suggest that Tvl-1, in combination with Tpl-2, promotes the assembly/stability of the Apaf-1 apoptosome while Akt either interferes with its assembly or promotes its dissociation. Tvl-1 and procaspase-9 associated with the complex assembled in the presence of the combination of Tvl-1 with Tpl-2 are both phosphorylated. As predicted from the preceding interactions, the caspase-9-dependent caspase-3 activation and apoptosis induced by Tpl-2 in immortalized non-transformed cell lines, was enhanced by Tvl-1. Ectopic expression of Tvl-1 also enhanced the TNFalpha-induced activation of caspase-3 and apoptosis in NIH3T3 cells. Independent studies by others revealed that Tvl-1 (RFXANK) contributes to the assembly/stability of a multimolecular transcriptional complex on the X site on class II MHC promoters. Mutations of the Tvl-1 gene silence these promoters, and they are responsible for complementation group B of the bare lymphocyte syndrome. The combination of the preceding data suggests that Tvl-1 is an adaptor protein that contributes to the assembly/stability of both cytoplasmic and nuclear multi-molecular complexes. This application addresses the role of Tvl-1 in the assembly and function of such complexes.