CLONING & CHARACTER OF C-MYC PROMOTER BINDING PROTEIN

C-myc原癌基因在肿瘤发生、发展过程中起重要作用。 细胞的生长和增殖。这个重要基因的表达是 在恶性和非恶性中受多种外部刺激的调节 细胞。我们已经证明c-myc的表达被选择性地抑制。 G-C特异性DNA结合药物米曲霉素。使用这种方法，我们拥有 鉴定位于P1和P2c-myc启动子5‘端的富含G-C的序列 它们结合了假定的调节因素。富含G-C的P1区结合 SP1调节蛋白但与富含G-C的P2区不同。我们已经使用了 将双链寡核苷酸连接到P2调控区以筛选 Cdna表达文库，并鉴定了一个基因 编码一种与该区域结合的蛋白质。这项提案将考验 假设c-myc启动子结合蛋白(MBP-1)是一个c-myc 调节蛋白，并在调节中发挥重要作用。 C-myc的表达。第二个c-myc启动子结合蛋白MBP-2，它 与P2启动子的ME1a2区结合，也已被鉴定。 它在调节c-myc表达中的作用也将被描述。 这项建议的具体目标是： 1.探讨MBP-1和MBP-2蛋白在肿瘤发生、发展中的作用。 C-myc启动子活性的调控。 2.研究MBP-1和MBP-2在细胞周期调控中的作用。 细胞增殖。 3.对MBP-2基因进行测序，并研究其与肿瘤细胞的相互作用 C-myc启动子序列。 4.纯化和鉴定重组和自然发生的 MBP-1和MBP-2基因的蛋白产物及其细胞鉴定 本地化。 这些研究将提供有关该法规的重要新信息。 并将使我们能够确定c-myc原癌基因的作用 C-myc启动子结合蛋白可能是一种myc调节蛋白。

The c-myc protooncogene plays an important role in the regulation of cellular growth and proliferation. Expression of this important gene is regulated by a number of external stimuli in malignant and nonmalignant cells. We have shown that c-myc expression is selectively inhibited by the G-C specific DNA binding drugs mithramycin. Using this approach we have identified G-C rich sequences located 5' of the P1 and P2 c-myc promoters which bind putative regulator factors. The G-C rich P1 region binds the Sp1 regulatory protein but with G-C rich P2 region does not. We have used double stranded oligonucleotides to the P2 regulatory region to screen a cDNA expression library and have identified and characterized a gene which encodes a protein binding to this region. This proposal will test the hypothesis that the c-myc promoter binding protein (MBP-1) is a c-myc regulatory protein and that it plays an important role in the regulation of c-myc expression. A second c-myc promoter binding protein, MBP-2, which binds to the ME1a2 region of the P2 promoter, has also been identified. Its role in the regulation of c-myc expression will also be characterized. The specific aims of this proposal are: 1. To investigate the role of the MBP-1 and MBP-2 proteins in the regulation of the c-myc promoter activity. 2. To characterize the role of MBP-1 and MBP-2 in the regulation of cellular proliferation. 3. To sequence the MBP-2 gene and to characterize its interaction with the c-myc promoter sequence. 4. To purify and characterize the recombinant and naturally occurring protein products of the MBP-1 and MBP-2 genes and determine their cellular localization. These studies will provide important new information about the regulation of the c-myc protooncogene and will allow us to determine the role of the c-myc promoter binding protein as a putative myc regulatory protein.