Rangarajan Sunita, Raj M L Stephen, Hernandez J Marcela, Grotewold Erich, Gopalan Venkat
Department of Biochemistry, The Ohio State University, 707 Biological Sciences Building, 484 West 12th Avenue, Columbus, OH 43210, USA.
Biochem J. 2004 Jun 15;380(Pt 3):611-6. doi: 10.1042/BJ20040442.
RNase P, a ribonucleoprotein responsible for the 5' maturation of precursor tRNAs (ptRNAs) in all organisms, can be enticed to cleave any target mRNA that forms a ptRNA-like structure and sequence-specific complex when bound to an RNA, termed the EGS (external guide sequence). In the present study, F3H (flavanone 3-hydroxylase), a key enzyme in the flavonoid biosynthetic pathway that participates in the formation of red-coloured anthocyanins, was used as a target for RNase P-mediated gene disruption in maize cells. Transient expression of an EGS complementary to the F3H mRNA resulted in suppression of F3H to 29% of the control, as indicated by a reduced number of anthocyanin-accumulating cells. This decrease was not observed in experiments where a disabled mutant EGS was expressed. Our results demonstrate the potential of employing plant RNase P, in the presence of an appropriate gene-specific EGS, as a tool for targeted degradation of mRNAs.
核糖核酸酶P（RNase P）是一种核糖核蛋白，负责所有生物体中前体tRNA（ptRNA）的5'端成熟。当与一种称为EGS（外部引导序列）的RNA结合时，它能被诱导切割任何形成ptRNA样结构和序列特异性复合物的靶标mRNA。在本研究中，黄酮类生物合成途径中的关键酶F3H（黄烷酮3-羟化酶）参与红色花青素的形成，被用作玉米细胞中RNase P介导的基因破坏的靶标。与F3H mRNA互补的EGS的瞬时表达导致F3H表达量降至对照的29%，这表现为积累花青素的细胞数量减少。在表达失活突变EGS的实验中未观察到这种下降。我们的结果证明了在存在合适的基因特异性EGS的情况下，利用植物RNase P作为靶向降解mRNA工具的潜力。
