The direct association between messenger RNA (mRNA) 3'-end processing
and the termination of transcription was established for the CYC1 gene
of Saccharomyces cerevisiae. The mutation of factors involved in the
initial cleavage of the primary transcript at the poly(A) site (RNA 14
, RNA 15, and PCF11) disrupted transcription termination at the 3' end
of the CYC1 gene. In contrast, the mutation of factors involved in th
e subsequent polyadenylation step (PAP1, FIP1, and YTH1) had little ef
fect. Thus, cleavage factors link transcription termination of RNA pol
ymerase II with pre-mRNA 3'-end processing.