When expressed in Various hosts the taz1(+) gene encoding the fission yeast telomere-binding protein produces two forms of polypeptides full-length (Taz1p) and truncated (Taz1p Delta C) version lacking almost entire Myb-domain Whereas Taz1p binds telomeric DNA in vitro, Taz1p Delta C forms long filaments unable of DNA binding. The formation of Taz1p Delta C is a result of neither site-specific proteolysis, nor premature termination of transcription In silico analysis of the taz1(+) RNA transcript revealed a stem-loop structure at the site of cleavage (cleavage box; CB) In order to explore whether it possesses inherent destabilizing effects, we cloned CB sequence into the open reading frame (ORF) Of gluthathione-S-transferase (GST) and observed that when expressed in Escherichia coli the engineered gene produced two forms of the reporter protein. The formation of the truncated version of GST was abolished, when CB was replaced with recoded sequence containing synonymous codons thus indicating that the truncation is based oil structural properties of taz1(+) mRNA. (C) 2010 Elsevier Inc All rights reserved