GTP BINDING PROTEINS AND ADENYLATE CYCLASE

GTP 结合蛋白和腺苷酸环化酶

• 批准号: 3857980
• 负责人: S-C TSAI
• 金额: --
• 依托单位: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3857980
• 关键词: ADP ribosylation; RNA splicing; adenylate cyclase; cholera toxin; cow; developmental neurobiology; enzyme induction /repression; enzyme mechanism; enzyme substrate; gel filtration chromatography; genetic promoter element; genetic transcription; guanine nucleotide binding protein; immunocytochemistry; laboratory rabbit; laboratory rat; polyadenylate

Cholera toxin, the secretory product of Vibrio cholerae responsible in part for the devastating diarrheal syndrome characteristic of cholera, activates adenylyl cyclase by catalyzing the ADP-ribosylation of Gs-alpha, the stimulatory guanine nucleotide-binding protein of the cyclase system. The toxin-catalyzed reaction is stimulated, in the presence of GTP, by approximately 20 kDa guanine nucleotide-binding proteins, termed ADP-ribosylation factors or ARFs. Rabbit polyclonal antibodies against bovine sARF II reacted with soluble and membrane ARFs but did not react with several other guanine nucleotide-binding proteins. The anti-ARF antibodies reacted with approximately 20 kDa ARF-like proteins in a variety of tissues from several species. The highest levels of immunoreactivity were observed in brain and other neural tissues. In other tissues, an immunoreactive band corresponding to SARF I was present. During rat brain development, when quantified by both immunoreactivity and function, SARF II was lowest at birth, increased somewhat by 10 days, and was maximal at 27-60 days; SARF I was unchanged. The increase of SARF II protein during postnatal development was paralleled by increased ARF 3 mRNA but not by mRNAs for five other ARFs. In the presence of GTP-gamma-S, ARF and toxin formed either an ARF-CTA complex in SDS (SDS) or self-associated ARF in DMPC/cholate, which were separated from monomeric ARF and CTA by gel filtration. Substrate specificities of ARF/toxin complexes were different from those of the monomeric proteins. The ARF 3 gene contains five exons and four introns and spans 18.3 kb. Two ARF 3 mRNAs are synthesized using alternative polyadenylation signals in exon 5. The gene appears to have multiple transcription start sites, no TATA box, no CAAT box and high G/C content in 5' promotor region. The ARF 1 gene is identical to the ARF 3 except that it has only one polyadenylation signal. The organization of the ARF 2 gene is identical to those of ARFs 1 and 3, although the promoter region is somewhat different and thus regulation of ARF 2 gene transcription may differ.

霍乱毒素是霍乱弧菌的分泌物 部分原因是毁灭性的梅毒综合征的特征， 通过催化ADP-核糖基化激活腺苷酸环化酶 Gs-alpha是一种刺激性的鸟嘌呤核苷酸结合蛋白， 环化酶系统 毒素催化的反应被刺激， GTP的存在，通过约20 kDa的鸟嘌呤核苷酸结合 蛋白质，称为ADP核糖基化因子或ARF。 兔多克隆 抗牛sARF II抗体与可溶性和膜性ARF反应 但不与其它几种鸟嘌呤核苷酸结合蛋白反应。 抗ARF抗体与约20 kDa的ARF样蛋白反应 存在于几个物种的多种组织中。 最高层 在脑和其他神经组织中观察到免疫反应性。 换句 组织中出现SARF Ⅰ免疫反应带。 在大鼠脑发育过程中，当通过免疫反应性和 功能，SARF II在出生时最低，10天后有所增加， 在27-60天达到最大值; SARF I无变化。 SARF II的增加 ARF 3 mRNA表达水平的增加， 但其他五种ARF的mRNA却没有。 在GTP-γ-S存在的情况下，ARF和毒素形成了 SDS（SDS）中的ARF-CTA复合物或DMPC/胆酸盐中的自相关ARF， 通过凝胶过滤从单体ARF和CTA中分离。 基板 ARF/毒素复合物的特异性不同于ARF/毒素复合物的特异性。 单体蛋白质 ARF 3基因包含5个外显子和4个内含子， 18.3 KB. 两个ARF 3 mRNA的合成使用交替多聚腺苷酸化 外显子5的信号。该基因似乎有多个转录起始点 5'启动子区无TATA盒和CAAT盒，G/C含量高。 ARF 1基因与ARF 3基因相同，除了它只有一个 多聚腺苷酸化信号。 ARF 2基因的组织结构是相同的 与ARF 1和3的启动子区域相比， 因此ARF 2基因转录的调节可能不同。