Thus, Hac1p of 230aa (220aa D 10aa) is translated from HAC1 precursor mRNA (1.
Obviously, there are two interpretations for these observations, depending on whether HAC1 precursor mRNA is translated or not.
27) Now Peter and I agree that ER stress-induced splicing of HAC1 precursor mRNA permits synthesis of the yeast UPR-specific transcription factor Hac1p.
mRNA splicing is usually carried out by the spliceosome in the nucleus; however, the sequences around the 5' and 3' splice sites in HAC1 precursor mRNA do not match the consensus sequence (GT-AG or AT-AC).
Both the 5' and 3' splice sites in HAC1 precursor mRNA form stem-loop structures (SL1 and SL4, respectively; Fig.
The above results predicted that ER stress-induced cleavage of HAC1 precursor mRNA involves a novel type of endonuclease.