PARN loss-of-function mutations cause a severe form of the hereditary disease dyskeratosis congenita (DC). PARN deficiency affects the stability of non-coding RNAs such as human telomerase RNA (hTR), but these effects do not explain the severe disease in patients. We demonstrate that PARN deficiency affects the levels of numerous miRNAs in human cells. PARN regulates miRNA levels by stabilizing either mature or precursor miRNAs by removing oligo(A) tails added by the poly(A) polymerase PAPD5, which if remaining recruit the exonuclease DIS3L or DIS3L2 to degrade the miRNA. PARN knockdown destabilizes multiple miRNAs that repress p53 translation, which leads to an increase in p53 accumulation in a Dicer-dependent manner, thus explaining why PARN-defective patients show p53 accumulation. This work also reveals that DIS3L and DIS3L2 are critical 3' to 5' exonucleases that regulate miRNA stability, with the addition and removal of 3' end extensions controlling miRNA levels in the cell.
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http://dx.doi.org/10.1016/j.molcel.2019.01.010 | DOI Listing |
Adv Sci (Weinh)
November 2024
State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
Diabetes, a metabolic disorder characterized by hyperglycemia, underscores the importance of normal pancreatic β-cell development and function in maintaining glucose homeostasis. Poly(A)-specific ribonuclease (PARN) serves as the principal regulator of messenger RNA (mRNA) stability, yet its specific role in pancreatic β cells remains unclear. This study utilizes mice with targeted PARN deficiency in β cells to elucidate this role.
View Article and Find Full Text PDFIn animal germ lines, The Piwi/piRNA pathway plays a crucial role in safeguarding genome integrity and promoting fertility. Following transcription from discrete genomic loci, piRNA precursors undergo nucleolytic processing at both 5' and 3' ends. The ribonuclease PARN-1 and its orthologs mediate piRNA 3' trimming in worms, insects and mammals.
View Article and Find Full Text PDFSci Rep
June 2023
Division of Molecular Genetics and Cancer, Nitte University Centre for Science Education & Research, NITTE (Deemed to be University), Deralakatte, Mangaluru, 575018, India.
Poly (A)-specific ribonuclease (PARN) is the most important 3'-5'exonuclease involved in the process of deadenylation, the removal of poly (A) tails of mRNAs. Although PARN is primarily known for its role in mRNA stability, recent studies suggest several other functions of PARN including a role in telomere biology, non-coding RNA maturation, trimming of miRNAs, ribosome biogenesis and TP53 function. Moreover, PARN expression is de-regulated in many cancers, including solid tumours and hematopoietic malignancies.
View Article and Find Full Text PDFFront Mol Neurosci
January 2023
Department of Biomedicine, Aarhus University, Aarhus, Denmark.
PCSK9 induces lysosomal degradation of the low-density lipoprotein (LDL) receptor (LDLR) in the liver, hereby preventing removal of LDL cholesterol from the circulation. Accordingly, PCSK9 inhibitory antibodies and siRNA potently reduce LDL cholesterol to unprecedented low levels and are approved for treatment of hypercholesterolemia. In addition, PCSK9 inactivation alters the levels of several other circulating lipid classes and species.
View Article and Find Full Text PDFAsian Pac J Cancer Prev
January 2022
Division of Molecular Genetics and Cancer, Nitte University Centre for Science Education and Research (NUCSER), NITTE (Deemed to be University), Deralakatte, Mangaluru, Karnataka, India.
Unlabelled: Ribonucleases (RNases) is the collective term used for the group of enzymes that are involved in mRNA degradation. The shortening of the poly (A) tail through deadenylation is the preferred mechanism of degradation of most eukaryotic mRNAs and poly (A)-specific ribonuclease (PARN) is the most important player in deadenylation. Besides its primarily role in mRNA stability, PARN is also involved in several non-conventional functions.
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