A reporter system recapitulates translation of N- and C-terminally truncated proteins from mRNAs containing nonsense variants. (A) Design of reporter constructs carrying the reference (sense) or alternate (nonsense) alleles of selected genes. (B) Cartoon depicting how permissive translation may enable productive translation of mRNAs containing nonsense variants, as well as the expected protein products from our reporter constructs for each mechanism of permissive translation. (C) Western blot of total protein from HEK293 cells transfected with constructs containing the reference alleles of all candidate genes. The FLAG and HA tags are illustrated in green and red. (White arrows) Constructs that produced the expected protein with both FLAG and HA tags. (D) As in C, but for constructs containing either the reference (Ref) or alternate (Alt) alleles of the genes marked with white arrows in C. For CCHCR1, the “Alt1” and “Alt2” variants correspond to SNVs at genomic positions 31,124,849 and 31,125,257 on Chromosome 6.
