UPF2 Created 2026-10-20 Updated 2026-11-05
UPF2 is an adaptor protein in nonsense-mediated decay that interacts with UPF1 and UPF3. These interactions help couple the context of an RNA-protein assembly to activation of the decay pathway. The role is regulatory and organizational rather than simply recognizing a particular three-base stop codon in isolation. Different substrates can depend differently on individual surveillance components. [ref]
Human Upf proteins target an mRNA for nonsense-mediated decay when bound downstream of a termination codon by Jens Lykke-Andersen and others. 2000, UPF protein interactions and tethering-dependent decay
UPF3 Created 2026-10-20 Updated 2026-11-05
UPF3 is a conserved factor associated with nonsense-mediated decay. In mammalian exon-junction-linked surveillance, UPF3 proteins can connect an exon-junction-associated assembly with UPF2 and downstream UPF1-dependent events. Human paralogues UPF3A and UPF3B differ in context and activity, so the generic label should not imply identical contributions in every cell. Artificial tethering experiments helped establish that positioning UPF factors downstream of a termination codon can promote decay. [ref]