Certain viruses, transposons, and cellular genes
have evolved specific sequences that induce high levels
of specific translational errors. Such “programmed
misreading” can result in levels of frameshifting
or nonsense codon readthrough that are up to 1,000-fold
higher than normal. Here we determine how a number of mutations
in yeast affect the programmed misreading used by the yeast
Ty retrotransposons. These mutations have previously
been shown to affect the general accuracy of translational
termination. We find that among four nonsense suppressor
ribosomal mutations tested, one (a ribosomal protein mutation)
enhanced the efficiency of the Ty1 frameshifting,
another (an rRNA mutation) reduced frameshifting, and two
others (another ribosomal protein mutation and another
rRNA mutation) had no effect. Three antisuppressor rRNA
mutations all reduced Ty1 frameshifting; however
the antisuppressor mutation in the ribosomal protein did
not show any effect. Among nonribosomal mutations, the
allosuppressor protein phosphatase mutation enhanced Ty1
frameshifting, whereas the partially inactive prion form
of the release factor eRF3 caused a slight decrease, if
any effect. A mutant form of the other release factor,
eRF1, also had no effect on frameshifting. Our data suggest
that Ty frameshifting is under the control of
the cellular translational machinery. Surprisingly we find
that translational suppressors can affect Ty frameshifting
in either direction, whereas antisuppressors have either
no effect or cause a decrease.