Polymerase-regulating component of the cleavage and polyadenylation factor (CPF) complex, which plays a key role in polyadenylation-dependent pre-mRNA 3'-end formation and cooperates with cleavage factors including the CFIA complex and NAB4/CFIB. Pre-mRNA polyadenylation factor that directly interacts with poly(A) polymerase PAP1. This inhibits the extension of an oligo(A) primer by limiting access of the RNA substrate to the C-terminal RNA binding domain of PAP1. Seems to tether PAP1 to the cleavage factor I. Component of the cleavage and polyadenylation factor (CPF) complex, which is composed of PTI1, SYC1, SSU72, GLC7, MPE1, REF2, PFS2, PTA1, YSH1/BRR5, SWD2, CFT2/YDH1, YTH1, CFT1/YHH1, FIP1 and PAP1. In the CPF complex probably interacts directly with PAP1 and YTH1. Interacts with RNA14. Circular dichroism measurements suggest that the protein is largely unstructured in the absence of interaction with PAP1. Present with 1310 molecules/cell in log phase SD medium. Belongs to the FIP1 family.