Reactome: A Curated Pathway Database

mRNA decay by 5' to 3' exoribonuclease (R-HSA-430039) [Homo sapiens]


Degradation of mRNA from 5' to 3' occurs in three steps. First, the mRNA is bound at its 3' end by the Lsm1-7 complex. The bound Lsm1-7 may prevent nucleases from accessing the 3' end. Second, the 7-methylguanosine cap of the mRNA is hydrolyzed by the DCP1-DCP2 complex. Third, the 5' end of the decapped mRNA is attacked by the XRN1 exoribonuclease which digests the remainder of the mRNA from 5' to 3'. These processes may be physically connected by PATL1, the homolog of yeast Pat1, which stably binds the Lsm1-7 complex and interacts with the DCP1-DCP2 decapping complex and the Ccr4-NOT deadenylation complex (Ozgur et al. 2010).