Mutations in UPF3B, a member of the nonsense-mediated mRNA decay complex, cause syndromic and nonsyndromic mental retardation. Tarpey PS, Raymond FL, Nguyen LS, Rodriguez J, Hackett A, Vandeleur L, Smith R, Shoubridge C, Edkins S, Stevens C, O'Meara S, Tofts C, Barthorpe S, Buck G, Cole J, Halliday K, Hills K, Jones D, Mironenko T, Perry J, Varian J, West S, Widaa S, Teague J, Dicks E, Butler A, Menzies A, Richardson D, Jenkinson A, Shepherd R, Raine K, Moon J, Luo Y, Parnau J, Bhat SS, Gardner A, Corbett M, Brooks D, Thomas P, Parkinson-Lawrence E, Porteous ME, Warner JP, Sanderson T, Pearson P, Simensen RJ, Skinner C,Nat Genet. 2007 Sep;39(9):1127-33. Epub 2007 Aug 19.
This gene encodes a protein that is part of a post-splicing multiprotein complex involved in both mRNA nuclear export and mRNA surveillance. The encoded protein is one of two functional homologs to yeast Upf3p. mRNA surveillance detects exported mRNAs with truncated open reading frames and initiates nonsense-mediated mRNA decay (NMD). When translation ends upstream from the last exon-exon junction, this triggers NMD to degrade mRNAs containing premature stop codons. This protein binds to the mRNA and remains bound after nuclear export, acting as a nucleocytoplasmic shuttling protein. It forms with Y14 a complex that binds specifically 20 nt upstream of exon-exon junctions. This gene is located on the long arm of chromosome 13. Two splice variants encoding different isoforms have been found for this gene. [provided by RefSeq
OTTHUMP00000018789,UPF3 regulator of nonsense transcripts homolog A