FUNCTION OF AN INTERFERON INDUCED UBIQUITIN HOMOLOG

干扰素诱导的泛素同系物的功能

• 批准号: 6519488
• 负责人: ARTHUR L HAAS
• 金额: $ 26.16万
• 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/6519488
• 关键词: biological signal transduction; chemical conjugate; enzyme mechanism; gene induction /repression; interferons; mass spectrometry; posttranslational modifications; protein isoforms; protein localization; protein protein interaction; protein sequence; protein structure function; proteomics; 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（改编自申请人的摘要）：干扰素诱导广泛 多效性作用，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 对抗病毒和寄生虫感染的活性，解释了对 这些细胞因子作为潜在的治疗剂。 ISG15 的引入 产生 17.1 kDa 多肽 ISG15 的基因是最早的基因之一 对 1 型干扰素的反应。 ISG15（以前称为 UCRP，泛素 交叉反应蛋白）是最近发现的一类交叉反应蛋白的原型 泛素样蛋白似乎调节细胞功能而不是 靶向易被 26S 蛋白酶体降解的蛋白质。在 与其他泛素样蛋白相比，ISG15 不存在于较低水平的细胞中。 真核生物，因此代表了相对较新的进化分歧。这 ISG15 的生物学效应是通过共价连接到 一小群细胞靶标与那些目标不同 其他泛素样蛋白。两种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统称 称为1-8族。 ca 14 kDa 多肽具有显着而又神秘的意义 与泛素缀合的保守催化结构域的序列相似性 酶（UBC）。本提案包括三个具体目标。具体目标 1 将测试 1-8 亚型代表 ISG15 特异性的假设 通过体外测定和稳定细胞转染来缀合酶 多肽的活性和显性突变形式。其他研究将 关注不同异构体之间的功能差异 潜在的底物特异性和细胞定位。具体目标2 将重点关注 9-27/Leu13 同工型及其在转导中的作用 抗增殖和同型粘附信号。其他研究将绘制地图 9-27 和普遍存在的四跨膜蛋白之间的蛋白质-蛋白质相互作用基序 CD81 及其与 CD19-CD21 的功能相互作用。具体目标 3 将 利用蛋白质组学和质谱蛋白质的最新进展 指纹识别以识别目标群体随时间的变化 静止状态和干扰素诱导状态下的 ISG15 结合。这些研究是 ISG15 缀合和酶学的首次协调功能调查 此修改。