mRNA decay pathway Staufen-mediated mRNA decay pathway PW:0000550 SMD pathway Staufen-mediated mRNA decay pathway (SMD) is a rather novel pathway identified in mammals. Staufen (Stau1) is thought to be involved in mRNA localization and it has recently been shown to be involved in mRNA decay. It shares some of the features of the nonsense-mediated mRNA decay pathway (NMD) but does not require components essential for NMD. pathway