FUNCTION OF AN INTERFERON INDUCED UBIQUITIN HOMOLOG

干扰素诱导的泛素同系物的功能

• 批准号: 6202892
• 负责人: ARTHUR L HAAS
• 金额: $ 25.7万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6202892
• 关键词: biological signal transduction; chemical conjugate; enzyme mechanism; functional /structural genomics; gene induction /repression; interferons; mass spectrometry; posttranslational modifications; protein isoforms; protein localization; protein protein interaction; protein sequence; protein structure function; tissue /cell culture; transfection; ubiquitin; yeast two hybrid system

DESCRIPTION (adapted from applicant's abstract): Interferons induce broad pleiotropic effects including growth inhibition, antitumor activity, hematopoietic regulation, control of cellular/humoral immune responses, and activity against viral and parasitic infection, accounting for interest in these cytokines as potential therapeutic agents. The induction of the ISG15 gene to generate the 17.1 kDa polypeptide ISG15 is one of the earliest responses to Type 1 interferons. ISG15 (formerly termed UCRP, the Ubiquitin Cross Reactive Protein) is the archetype of a recently discovered class of ubiquitin-like proteins that appear to regulate cellular function rather than to target susceptible proteins for degradation by the 26S proteasome. In contrast to the other ubiquitin-like proteins, ISG15 is not present in lower eukaryotes and thus represents a relatively recent evolutionary divergence. The biological effects of ISG15 are exerted through its covalent ligation to a small population of cellular targets that is distinct from those targeted by other ubiquitin-like proteins. Two-hybrid screens have recently identified a small class of highly conserved late interferon-induced proteins collectively termed the 1-8 family. The ca 14 kDa polypeptides bear remarkable yet cryptic sequence similarity to the conserved catalytic domain of ubiquitin conjugating enzymes (Ubc). The present proposal comprises three specific aims. Specific Aim 1 will test the hypothesis that 1-8 isoforms represent ISG15-specific conjugating enzymes through in vitro assays and stable cell transfections of active and dominant mutant forms of the polypeptides. Other studies will concentrate on functional differences among the different isoforms with respect to potential substrate specificity and cellular localization. Specific Aim 2 will focus on the 9-27/Leu13 isoform and its role in transducing antiproliferative and homotypic adhesion signals. Other studies will map protein-protein interaction motifs between 9-27 and the ubiquitous tetraspanin CD81 and their functional interactions with CD19-CD21. Specific Aim 3 will exploit recent advances in proteomics and mass spectroscopic protein fingerprinting to identify time-dependent changes in populations of targets for ISG15 conjugation in quiescent and interferon induced states. These studies are the first concerted functional survey of ISG15 conjugation and the enzymology of this modification.

描述(改编自申请者摘要)：干扰素引起广泛 多效性，包括生长抑制，抗肿瘤活性， 造血调节，细胞/体液免疫反应的控制，以及 抗病毒和寄生虫感染的活性，占感兴趣的 这些细胞因子是潜在的治疗剂。ISG15的引入 基因产生的17.1 kDa多肽ISG15是最早的 对1型干扰素的反应。ISG15(以前称为UCRP，泛素 交叉反应蛋白)是最近发现的一类 泛素样蛋白似乎调节细胞功能，而不是 以26S蛋白酶体降解易感蛋白为靶点。在……里面 与其他泛素样蛋白不同，ISG15不存在于 因此代表了一种相对较新的进化分化。这个 ISG15的生物学效应是通过其共价连接到 细胞靶标数量较少，不同于 其他泛素样蛋白。双混合屏幕最近发现了一种 小类高度保守的晚期干扰素诱导蛋白 被称为1-8家庭。约14 kDa的多肽具有非凡而神秘的特点 泛素结合保守催化结构域的序列相似性 酵素(UBC)。目前的建议包括三个具体目标。特定目标 1将检验1-8个亚型代表ISG15特异性的假设 结合酶的体外检测和稳定的细胞转染 多肽的活性和显性突变形式。其他研究将 专注于不同异构体之间的功能差异 与潜在的底物专一性和细胞定位有关。具体目标2 将重点介绍9-27/Leu13亚型及其在转导中的作用 抗增殖和同型黏附信号。其他研究将绘制地图 9-27与广泛存在的Tetraspanin之间的蛋白质相互作用模体 CD81及其与CD19-CD21的功能相互作用具体目标3将 蛋白质组学和质谱学的最新进展 识别目标种群随时间变化的指纹图谱 静止状态和干扰素诱导状态下的ISG15结合。这些研究是 ISG15结合蛋白的首次协同功能研究及酶学研究 这一修改。