PARN

Description

The PARN (poly(A)-specific ribonuclease) is a protein-coding gene located on chromosome 16.

PARN is an enzyme, encoded by the PARN gene, that removes the poly(A) tail from messenger RNA (mRNA) molecules. This process, known as deadenylation, is a critical step in the decay of eukaryotic mRNAs. PARN shares similarities with the RNase D family of 3'-exonucleases and is found in both the nucleus and cytoplasm of cells. Mutations in the PARN gene can lead to dyskeratosis congenita, a bone marrow failure disease caused by defective telomerase RNA processing and degradation.

PARN is a 3'-exoribonuclease that specifically targets and degrades poly(A) tails of mRNAs. This process is crucial for mRNA decay, acting as the initial step in the breakdown of eukaryotic mRNAs. PARN also plays a role in silencing maternal mRNAs during oocyte maturation and early embryonic development. It interacts with both the poly(A) tail and the 5'-cap structure of mRNAs, with the cap interaction being necessary for efficient poly(A) tail degradation. PARN is involved in nonsense-mediated mRNA decay, a mechanism that degrades mRNAs containing premature stop codons. It also participates in the degradation of unstable mRNAs containing AU-rich elements (AREs) in their 3'-UTR, potentially through its interaction with KHSRP. This degradation process likely involves the removal of poly(A) tails from AREs mRNAs, marking the first step of their destabilization. PARN can also recognize and trim poly(A) tails of microRNAs like MIR21 and H/ACA box snoRNAs, influencing microRNA degradation or snoRNA stability.

PARN is also known as DAN, DKCB6, PFBMFT4.

Associated Diseases

• Idiopathic pulmonary fibrosis
• Hoyeraal-Hreidarsson syndrome
• Dyskeratosis congenita, autosomal recessive 6
• Pulmonary fibrosis and/or bone marrow failure, telomere-related, 4
• Dyskeratosis congenita