FUNCTIONS OF SV40 SMALL-T ANTIGEN AND CELLULAR PROTEINS

本研究的总体目标是确定 SV 40小T抗原和两种细胞蛋白， 合伙人 主要精力将放在研究代谢 表达小T抗原的细胞模式，因为最近的研究 表明抗线粒体药物和离子载体改变了生长模式， 在CV-1细胞中观察到，这与小T抗原的存在有关。 质膜功能，如运输和膜电位，将 也可检测与小T抗原相关的抗原。 我们还将继续观察细胞蛋白质之一，32 K， 似乎结合S-腺苷甲硫氨酸（SAM）。 这就提出了一个 32 K蛋白可能是一种利用SAM作为酶的酶。 基质，并可能提供一个主要线索，有关的功能，至少 一种细胞蛋白质，间接地，小T细胞的功能 抗原的 小T抗原和细胞蛋白的纯化， 继续进行并扩大，特别强调 由细菌克隆表达的可溶性小T抗原。 分离 小T抗原保留了与细胞相互作用的能力， 蛋白质是优先考虑的。 另外的努力包括开发杂交瘤细胞系， 识别小T抗原细胞蛋白复合物的抗体 或者识别小T抗原的独特区域。 如果 后者是获得，试图鉴定和活性蛋白片段 将从受感染细胞中的小T抗原制备。 势函数 这种片段也可以用细菌克隆来处理， 含有仅来自小t抗原的该区域的DNA序列， 所述小T独特序列可以在细菌中表达。

The overall aim of this research is the determination of the functions of SV40 small-t antigen and of two cellular proteins with which it associates. Major effort will be placed on investigations of the metabolic patterns of cells that express small-t antigen, because recent studies have shown that antimitochondrial drugs and ionophores modify growth patterns observed in CV-1 cells which relate to the presence of small-t antigen. Plasma membrane functions, such as transport and membrane potential, will also be examined and related to small-t antigen. We will also pursue the observation that one of the cellular proteins, 32K, appears to be binding S-adenosylmethionine (SAM). This raises the possibility that the 32K protein may be an enzyme which uses SAM as a substrate, and may provide a major clue concerning the function of at least one of the cellular proteins and, indirectly, the function of small-t antigen. Purifications of small-t antigen and the cellular proteins will be continued and scaled-up, with particular emphasis on purification of the soluble small-t antigen expressed by a bacterial clone. Isolation of small-t antigen which retains the ability to interact with the cellular proteins is a priority. Additional efforts include development of hybridoma cell lines that produce antibodies that recognize the small-t antigen cellular protein complex efficiently, or that recognize the unique region of small-t antigen. If the latter is obtained, attempts to identify and active protein fragment from small-t antigen in infected cells will be made. Potential function of such a fragment is also being approached using a bacterial clone that contains DNA sequences only from this region of small-t antigen, and from which small-t unique sequences can be expressed in bacteria.