P-2: LANA-1 mediated negative regulation of gene expression

卡波西肉瘤相关疱疹病毒，KSHV，与恶性卡波西肉瘤相关。 肉瘤、原发性渗出性淋巴瘤和Castleman病。这些癌症的发病率 在艾滋病患者身上。KSHV潜伏期相关核抗原拉娜/LANA 1在所有KSHV中表达 感染的细胞和相关的癌症。拉娜是一种多功能蛋白， 复制和维持附加型KSHV基因组，还具有转录调节特性。 已知拉娜通过上调E2 F和通过Wnt/mRNA的表达来激活细胞基因的表达。 β-连环蛋白途径。然而，当作为Gal 4-融合物与DNA连接时，拉娜也能够 抑制转录和基因阵列研究也报道了LANA介导的转录抑制。的 拉娜可能抑制基因表达的方式还不清楚，也不清楚细胞基因的全部范围。 已知目标转录沉默可能有助于KSHV潜伏期的维持和KSHV的表达。 KSHV相关恶性肿瘤的发展，因此建议研究拉娜的这一方面 功能 实验的重点将是在基因阵列分析中被识别为被抑制的基因。的 将评估对拉娜相互作用蛋白MeCP 2和sp 100-HMG的抑制的贡献。我们 先前已经证明了这些蛋白质在将拉娜束缚到细胞染色体中的作用，现在 提出这些蛋白质可能在LANA介导的抑制中具有双重功能。此外 新发现的拉娜和DNA甲基转移酶之间的相互作用以及拉娜和 将研究转录因子。个人目标将解决：（一）组蛋白的贡献 去乙酰化酶和DNA甲基转移酶对中度与强烈抑制的 启动子，（ii）MeCP 2和sp100-HMG在阻遏中的作用的研究，（iii） （iv）在拉娜介导的阻遏中LANA介导的阻遏的评估 临床标本

The Kaposi's sarcoma associated herpesvirus, KSHV, is associated with the malignancies Kaposi's sarcoma, primary effusion lymphoma and Castleman's disease. These cancers have an increased incidence in patients with AIDS. The KSHV latency associated nuclear antigen LANA/LANA1 is expressed in all KSHV infected cells and in the associated cancers. LANA is a multi-functional protein that is essential for replication and maintenance of episomal KSHV genomes and also has transcriptional regulatory properties. LANA is known to activate expression of cellular genes through upregulation of E2F and through the Wnt/ beta-catenin pathway. However, when tethered to DNA as a Gal4-fusion, LANA is also capable of repressing transcription and gene array studies also report LANA-mediated transcriptional repression. The ways in which LANA might repress gene expression are not understood nor are the full range of cell gene targets known. Transcriptional silencing is likely to contribute to maintenance of KSHV latency and to the development of KSHV associated malignancies and hence it is proposed to investigate this aspect of LANA's function. The experimental focus will be on genes identified in gene array analyses as being repressed. The contribution to repression of the LANA interacting proteins MeCP2, and sp100-HMG will be evaluated. We have previously demonstrated a role for these proteins in tethering LANA to cell chromosomes and now propose that these proteins might have a dual function in LANA-mediated repression. In addition the contribution of newly identified interactions between LANA and DNA methyl transferases and LANA and transcription factors will be investigated. The individual aims will address: (i) The contribution of histone deacetylases and DNA methyl transferases to the repression of moderately versus strongly repressed promoters, (ii) Investigation of the role of MeCP2 and sp100-HMG in repression, (iii) Examination of transcription factor interactions in LANA mediated repression (iv) Evaluation of LANA-mediated repression in clinical specimens.