Involvement of Pta1, Pcf11 and a KlCYC1 AU-rich element in alternative RNA 3′-end processing selection in yeast

This work reports the involvement of yeast RNA processing factors Pta1 and Pcf11 in alternative 3′-end RNA processing. The pta1-1 and pcf11-2 mutations changed the predominance of KlCYC1 1.14 and 1.5 kb transcript isoforms. Mutation of the KlCYC1 3′-UTR AU-rich sequence at positions 679–690 (mutant M1) altered transcript predominance. Moreover, expression of M1 in the yeast mutants partially suppressed their effects in the predominance pattern. The combination of the M1 and M2 (694–698 deletion) mutations abolished the alternative processing. Pta1 involvement in this selection was confirmed using the Pta1-td degron strain.