TRANSFORMATION BY AVIAN RETICULOENDOTHELIOSIS VIRUS

禽网状内皮组织增生病病毒（REV-T）是禽流感病毒中 所有的逆转录病毒。 REV-T的癌基因v-rel转化和 阻止淋巴细胞随后的分化， B细胞发育的不同阶段。 REV-T转换正常 细胞转化为致瘤状态提供了一个很好的模型， 致癌机制的研究。 v-rel癌基因是不同的 来自其他已知的癌基因，并编码一种59 kDa的蛋白， 与一组独特的细胞蛋白质有关。 存在两种pp 59 v-rel胞质复合物，其含有 c-rel原癌基因的产物（p75 c-rel）和组成型 热休克蛋白70（p70 HSC） 主要胞质 复合物的独特之处在于它含有一个40 kDa的磷蛋白 （第40页）。 细胞质中20%的pp 59 v-rel不是 与pp 40相关，但与两种高分子量蛋白质相关 (p115，p124）。 纯化的pp 59 v-rel胞质复合物含有 相关的丝氨酸激酶活性。 大约百分之十的 PP 59 V-REL存在于含有PP 40的核复合物中。 在正常禽类淋巴样细胞中，p75 c-rel与蛋白质复合 与pp 59 v相关的表观分子量相同， REV-T转化细胞中的rel。 主要的p75 c-rel复合物 含有p115和p124。 丰度较低的复合物含有p75 c- 与pp 40相关的rel。 c-rel原癌基因和v-rel蛋白激活转录 在酵母中，负责激活的区域也是 V-rel的致癌转化所必需的。 但在 正常和转化的禽类淋巴样细胞p75 c-rel是一种胞质的 蛋白 p75 c-rel可能是一种反式激活因子， 被隔离在未受刺激的淋巴细胞的胞质溶胶中。 当 REV-T转化细胞暴露于重金属、p75 c-rel 水平增加并发生核转位。 目标 1）对v-rel进行突变分析， 将转化能力与细胞结合 蛋白质与v-rel蛋白质的结合; 2）确定这些蛋白质中的任何一种是否 与p75 c-rel相关的蛋白质参与了细胞核内 3）分子克隆并测序编码 pp 40的表达，并确定其组织特异性表达; 针对与以下相关的细胞蛋白的单克隆抗体 pp59v-rel和p75c-rel。

Avian reticuloendotheliosis virus (REV-T) is the most virulent of all retroviruses. The oncogene of REV-T, v-rel, transforms and prevents the subsequent differentiation of lymphoid cells at different stages of B cell development. REV-T converts normal cells to a tumorigenic state providing an excellent model for studies on oncogenic mechanisms. The v-rel oncogene is distinct from other known oncogenes and encodes a 59 kDa protein which is associated with a distinct set of cellular proteins. There are two pp59v-rel cytosolic complexes which contain the product of the c-rel proto-oncogene (p75c-rel) and the constitutive form of heat shock protein 70 (p70hsc). The major cytosolic complex is distinct in that it contains a 40 kDa phosphoprotein (pp40). Twenty percent of pp59v-rel in the cytosol is not associated with pp40 but with two high molecular weight proteins (p115, p124). Purified pp59v-rel cytosolic complexes contain an associated serine kinase activity. Approximately ten percent of the pp59v-rel is present in nuclear complexes which contains pp40. In normal avian lymphoid cells p75c-rel is complexed with proteins of the same apparent molecular mass as those associated with pp59v- rel in REV-T transformed cells. The major p75c-rel complex contains p115 and p124. The less abundant complex contains p75c- rel associated with pp40. The c-rel proto-oncogene and v-rel proteins activate transcription in yeast and the region responsible for activation is also necessary for oncogenic transformation by v-rel. However, in normal and transformed avian lymphoid cells p75c-rel is a cytosolic protein. It is likely p75c-rel is a transactivating factor which is sequestered in the cytosol of unstimulated lymphoid cells. When REV-T transformed cells are exposed to heavy metals, p75c-rel levels increase and nuclear translocation occurs. The objectives of this proposal are to 1) perform mutational analysis on v-rel to correlate transforming ability with the binding of cellular proteins to the v-rel protein; 2) determine whether any of these proteins associated with p75c-rel are involved in nuclear translocation; 3) molecularly clone and sequence the gene encoding pp40 and define its tissue specific expression; 4) prepare monoclonal antibodies against the cellular proteins associated with pp59v-rel and p75c-rel.