Fig. 7
From: Common mechanism of transcription termination at coding and noncoding RNA genes in fission yeast
Transcription termination at lncRNA genes and general model for 3′ end processing and transcription termination of mRNA and snoRNA genes in fission yeast. a–c Normalized ChIP-seq signal of total RNAPII (Rpb1 and Rbp3-HA), the indicated CTD modifications, and 3′ end processing factors across the SPNCRNA.532 (a), the SPNCRNA.491 (b), and the nam1/SPNCRNA.1459 (c) genes. d, e Recruitment of cleavage and polyadenylation factors (CPF) by poly(A) signals (PAS) is a common feature of mRNA and snoRNA genes (see Cleavage). Endonucleolytic cleavage by the CPF-associated Ysh1 nuclease will generate an RNAPII-bound unprotected 5′ end that will be targeted by the 5′–3′ exonuclease Dhp1, contributing to termination of mRNA and snoRNA transcription (see Termination). The RNA-bound CPF complex promotes snoRNA 3′ end maturation, possibly by facilitating Pab2 recruitment to snoRNA precursors. The co-transcriptional recruitment of specific export factors to nascent mRNAs (d) may represent a decisive step that prevents Pab2-dependent exosome-mediated RNA processing in the nucleus (e)
