Kiss your tail goodbye: The role of PARN, Nocturnin, and Angel deadenylases in mRNA biology

Abstract

PARN, Nocturnin and Angel are three of the multiple deadenylases that have been described in eukaryotic cells. While each of these enzymes appear to target poly(A) tails for shortening and influence RNA gene expression levels and quality control, the enzymes differ in terms of enzymatic mechanisms, regulation and biological impact. The goal of this review is to provide an in depth biochemical and biological perspective of the PARN, Nocturnin and Angel deadenylases. Understanding the shared and unique roles of these enzymes in cell biology will provide important insights into numerous aspects of the post-transcriptional control of gene expression.

Polysomes, Stress Granules, and Processing Bodies: A Dynamic Triumvirate Controlling Cytoplasmic mRNA Fate and Function

“…The first is the EEP-type deadenylase Nocturnin that is distinguished by its circadian clock-regulated transcript abundance in multicellular eukaryotes (Godwin et al, 2013). Arabidopsis HESPERIN (AtHESP) is closely related to mammalian Nocturnin, with maximal mRNA levels in the evening.…”

“…The second is the homodimeric DEDD-class PARNs found in plants and humans but apparently absent from budding yeast (Saccharomyces cerevisiae) and fruit flies (Drosophila melanogaster; Godwin et al, 2013). Arabidopsis PARN (AtPARN)/ABA HYPERSENSI-TIVE GERMINATION2 (AHG2) is required for the poly(A) tail shortening of select embryonic transcripts, affecting embryonic development and some stress responses (Chiba et al, 2004;Reverdatto et al, 2004;Nishimura et al, 2005).…”

Regulatory roles of vertebrate Nocturnin: insights and remaining mysteries

“…However, the collection of deadenylases is larger than expected if all deadenylases were fully interchangeable. Although a comprehensive review of the specific functions attributed to each deadenylase is beyond the scope of this article (readers are instead referred elsewhere [13,21,24–26]), several lines of evidence support functional specialization amongst these proteins, even among the most closely-related of these enzymes. The strongest support for this idea comes from analyses of vertebrate NOCT, CNOT7, and CAF1z loss-of-function models that exhibit distinct phenotypes, indicating unique functions for these enzymes [9,27–30].…”

“…In addition to regulation of body mass, NOCT affects the regulation of intestinal lipid trafficking, and the differentiation of bone marrow mesenchymal stem cells into either adipocytes or osteoblasts (Fig. 1) [18–21]. As a putative RNA decay factor, NOCT has been proposed to contribute to these processes by destabilizing mRNAs encoding proteins with important metabolic and developmental functions.…”

FXR1a-associated microRNP: A driver of specialized non-canonical translation in quiescent conditions

“…83,89 PARN is localized to both the nucleus and cytoplasm and is known to play a role in gene expression regulation. 64,[90][91][92] PARN plays an important role during oocyte development by regulating poly (A) tail length and thereby, translation. 64,93 Besides its role in early development, PARN has been implicated in certain cancers, in Dyskeratosis congenita, and in pulmonary fibrosis.…”