GROWTH RATE CONTROL OF RNA DECAY

RNA 衰变的生长速率控制

• 批准号: 2293120
• 负责人: CARINA E GAGGERO
• 金额: $ 2.58万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-30 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2293120
• 关键词: GROWTH; RATE; CONTROL; RNA; DECAY

A key element of control of ColE1-type plasmids in vivo is the rate of degradation of the antisense repressor RNAI. Endonucleolytic removal of 5 bp from the 5' end of RNAI by RNaseE relieves repression converting RNAI to pRNAI-5' a rapidly decaying product. An artificially constructed 5'triphosphate-terminated homolog of pRNAI-5' pppRNAI-5' is degraded slowly and consequently inhibits replication. The decay of pppRNAI-5' which lacks an RNaseE cleavage site, is markedly affected by the rate of cell growth. When bacterial growth is slowed, the cellular concentration of pppRNAI-5 increases, plasmid DNA replication is inhibited and plasmid copy number decreases. The aim of this project is to identify the growth-rate controlled enzyme (GRCE) that degrades the 5'triphosphate terminus of this RNAI variant. Since pRNAI-5 and pppRNAI-5 are identical except for the mono or triphosphate 5' terminus, it is likely that the difference in decay rate results from a 5'-exonucleolytic activity. Mutations that increase the activity or expression of the GRCE will be isolated selecting for an increase of plasmid copy number in conditions of slowed cell growth. After cloning the gene encoding this enzyme, regulatory regions will be identified and response to cell growth at the level of gene expression will be tested. The long-term objective is to investigate how changes in cell growth rate can affect the degradative pathway of an RNA.

Cole1型质粒在体内控制的关键要素是 反义阻遏物RNAi的降解。 内核解释性清除 RNASEE的RNAi 5'末端的5 bp可缓解抑制转换 RNAi至PRNAi-5'迅速衰减的产品。 人为构造的 prNAi-5“ ppprnai-5”的5'triphosphate终止同源物被降解 慢慢地抑制复制。 ppprnai-5'的衰变 缺少RNASEE裂解位点，受到明显影响 细胞生长。 当细菌生长减慢时，细胞浓度 ppprnai-5的增加，质粒DNA复制被抑制和质粒 拷贝数减少。 该项目的目的是确定增长率受控酶 （grce）降低了该RNAi变体的5'triph磷酸盐末端。 由于Prnai-5和Ppprnai-5除非单声道或 三磷酸5'末端，衰减率的差异很可能 来自5'-核酸化活性的结果。 增加的突变 将分离出GRCE的活动或表达 在细胞生长缓慢的条件下，质粒拷贝数的增加。 克隆编码该酶的基因后，调节区域将是 鉴定并对基因表达水平的细胞生长的反应 将进行测试。 长期目标是调查如何改变 细胞生长速率可能会影响RNA的降解途径。