Stop codon read-through?

[Harris Laboratory]

Is there any evidence for read-through on a UAG stop codon? If so what
examples are available?

We have a cDNA sequence that contains an addition of 45 bp.  This
causes an codon shift that results in a premature stop codon.  This
should yield a 11 kDa protein when translated.  However in in vitro
translation system, a 59 kDa protein is generated & detected via
Western analysis.

Any help would be appreciated.