CHARACTERIZATION OF ANGIOTENSIN BINDING IN CELLS TRANSFECTED WITH MAS ONCOGENE

血管紧张素（人mas癌基因）的一种假定受体， 通过共转染NIH-3 T3细胞并进行致瘤性测定来检测， 从人表皮样癌中分离的DNA。 这些报告表明， 这个基因在转染后的重排导致了 人mas基因的激活和随后的转化（Foci 形成能力）。 注射这些 转化的细胞进入裸鼠体内形成肿瘤。 转化分析 3 T3细胞表明，有一种蛋白质的合成增加， 能够结合血管紧张素II和血管紧张素III。 免疫荧光分析， 抗肽-针对第1和第2细胞外 Mas多肽的结构域支持了Mas多肽的表达增加， 受体的合成。 综上所述各项 结果提示MAS基因产物参与细胞生长， 增殖 Mas蛋白是否作为血管紧张素 受体或作为刺激结合的生长因子的结合位点 或者血管紧张素和细胞的结合是否增加 由于Mas的存在而导致的生长是细胞类型选择性的， 完全理解 因此，本建议的目标是：（i） 表征血管紧张素在转染的NIH-3 T3细胞中结合 人mas基因，（ii）确定mas基因在调节 细胞生长和增殖，（III）确定细胞是否响应 mas表达是细胞类型或机制特异性的，和（iv） 相关mas基因表达和血管紧张素受体活性， 妊娠和非妊娠家兔的子宫。 学生（包括毕业生和 本科生）预计将参与这方面的各个方面 提议

A putative receptor for angiotensin (mas oncogene from human) was detected by cotransfection and tumorigenicity assay of NIH-3T3 cells with DNA isolated from Human epidermoid carcinoma. These reports suggested that rearrangement of this gene after transfection resulted in the activation of the Human mas gene and subsequent transformation (Foci forming ability) of the transfected cells. Injection of these transformed cells into nude mice form tumors. Analysis of transformed 3T3 cells suggest that there is an increased synthesis of a protein capable of binding Ang II and Ang III. Immunofluorescence analysis using antipeptide-antibodies generated against the 1st and 2nd extracellular domains of the Mas polypeptide support the presence of an increase in receptor synthesis in transplanted 3T3 cells. Taken together, these results suggest that the mas gene product participates in cell growth and proliferation. Whether the Mas protein functions as an angiotensin receptor or as a binding site for growth factors stimulating the binding of angiotensin, or whether the increased binding of angiotensin and cell growth resulting from the presence of Mas is cell-type selective is not fully understood. Therefore, the objectives of this proposal are (i) to characterize the binding of angiotensin in NIH-3T3 cells transfected with the human mas gene, (ii) to determine the role of mas gene in regulating cell growth and proliferation, (III) to determine if the cells response to mas expression is cell-type or mechanism specific, and (iv) to correlate mas gene expression and angiotensin receptor activities in uteri of pregnant and non-pregnant rabbits. Students (both graduate and undergraduate) are expected to participate in all aspects of this proposal.