TENT4B, also known as PAPD5, is a noncanonical poly(A) polymerase that contains a C-terminal RNA binding domain []. It is responsible for addition of the oligo(A) tails of H/ACA box snoRNA followed by its 3'-to-5' trimming by the exoribonuclease PARN which enhances snoRNA stability and maturation [, ]. Together with the poly(A)-specific ribonuclease PARN, PAPD5 is involved in miR-21 degradation [].
TENT4A, also known as PAPD7, is a non-canonical poly(A) polymerase []. Together with TENT4B (also known as PAPD5), it generates specialized tails that protect mRNAs from active deadenylation [].
