UPF3B regulator of nonsense-mediated mRNA decay (UPF3B)

UPF3B regulator of nonsense-mediated mRNA decay (UPF3B) is a critical auxiliary component of the nonsense-mediated mRNA decay (NMD) pathway, a conserved post-transcriptional gene regulatory mechanism that degrades mRNAs containing premature termination codons to prevent the production of potentially harmful truncated proteins[1][3][5]. UPF3B acts as a modular RNA-binding factor, containing an RNA recognition motif-like domain (RRM-L), a NONA/paraspeckle-like domain (NOPS-L), and an extended α-helical domain essential for binding mRNA and ribosomes as well as interacting with UPF2, another central NMD factor[1][3]. UPF3B, along with its paralog UPF3A, modulates NMD in a tissue- and cell-type dependent manner and also plays a role in neurodevelopment, including in neuronal differentiation and branching[1][3][5]. Pathogenic mutations in UPF3B cause X-linked intellectual disability and have been associated with autism and schizophrenia, largely due to impaired mRNA decay and altered regulation of neuronal mRNA targets[1][3][4]. UPF3B is not a traditional therapeutic target (such as a receptor or enzyme targeted by drugs), but it is a disease-relevant RNA-binding protein and gene expression regulator, with clinical relevance in genetic disorders caused by NMD malfunction[1][3].

Other names

UP-frameshift 3-BRegulator of nonsense-mediated mRNA decay UPF3BNMD factor UPF3B