关于RNA pyrophosphohydrolase： Messenger RNA (mRNA) degradation plays a key role in the control of gene expression in all organisms by limiting the number of times that each mRNA molecule can be used as a template for protein synthesis. RNA pyrophosphohydrolase, also called RppH, is a master regulator of 5-dependent mRNA decay. It accelerates the degradation of transcripts by removing pyrophosphate from the 5-end of triphosphorylated RNA, leading to a more labile monophosphorylated state that can stimulate subsequent ribonuclease cleavage. RppH preferentially hydrolyzes diadenosine penta-phosphate with ATP as one of the reaction products, and can be able to hydrolyze diadenosine hexa- and tetra-phosphate. However, this protein has no activity on diadenosine tri-phosphate, ADP-ribose, NADH and UDP-glucose. In the meningitis causing strain E.coli K1, it has been shown to play a role in HBMEC (human brain microvascular endothelial cells) invasion in vitro.
