“Cradle to grave” describes one protein's relationship with mRNA. As Lotan et al. reveal, the protein helps make mRNA and helps destroy it. The molecule, a piece of RNA polymerase II, might permit cells to coordinate mRNA synthesis and breakdown.
Cells degrade mRNA to eliminate damaged strands and manage protein synthesis. Enzymes first strip off the molecule's tail of multiple adenines. The demolition then sometimes proceeds from the 5′ to the 3′ end, usually in cytoplasmic structures called P-bodies. Or enzymes can chop up the strand in the 3′-to-5′ direction. The RNA polymerase II complex weaves new strands of mRNA, but previous work by the researchers suggested that one of its components, Rpb4p, also helps initiate destruction. However, Rpb4p lacks a site for grabbing RNA, implying that it gets help.
Lotan et al. tested whether that aid comes from Rpb4p's partner, the RNA-binding protein Rpb7p....
