Identification and molecular characterization of cellular factors required for glucocorticoid receptor-mediated mRNA decay

Abstract

Glucocorticoid (GC) receptor (GR) has been shown recently to bind a subset of mRNAs and elicit rapid mRNA degradation. However, the molecular details of GR-mediated mRNA decay (GMD) remain unclear. Here, we demonstrate that GMD triggers rapid degradation of target mRNAs in a translation-independent and exon junction complexindependent manner, confirming that GMD is mechanistically distinct from nonsense-mediated mRNA decay (NMD). Efficient GMD requires PNRC2 (proline-rich nuclear receptor coregulatory protein 2) binding, helicase ability, and ATM-mediated phosphorylation of UPF1 (upstream frameshift 1). We also identify two GMD-specific factors: an RNA-binding protein, YBX1 (Y-box-binding protein 1), and an endoribonuclease, HRSP12 (heat-responsive protein 12). In particular, using HRSP12 variants, which are known to disrupt trimerization of HRSP12, we show that HRSP12 plays an essential role in the formation of a functionally active GMD complex. Moreover, we determine the hierarchical recruitment of GMD factors to target mRNAs. Finally, our genome-wide analysis shows that GMD targets a variety of transcripts, implicating roles in a wide range of cellular processes, including immune responses.

HuR stabilizes a polyadenylated form of replication‐dependent histone mRNAs under stress conditions

“…S1). The HP in the 59 UTR has been demonstrated to drastically inhibit translation (29,31). Puro treatment increased the relative amounts of exogenously expressed poly(A) + HIST1H4K mRNAs regardless of the presence of the HP in the 59 UTR (Fig.…”

“…HeLa cells were grown in DMEM supplemented with 10% (v/v) fetal bovine serum and 1% (v/v) penicillin/streptomycin solution (all from GE Healthcare Korea, Seoul, South Korea). The cells were transiently transfected with the plasmids or 100 mM final synthetic siRNAs (GenePharma, Shanghai, China) by using Lipofectamine 2000 (Thermo Fisher Scientific) or Oligofectamine (Thermo Fisher Scientific), respectively (29)(30)(31)(32). Total-cell RNA and protein were prepared as previously described (28,33).…”

Twenty-First Century Glucocorticoid Receptor Molecular Biology

“…The observation that GR complies with chromosome conformation rather than influencing it offers the exciting perspective of Figure 3. Model of the assembly and composition of the glucocorticoid mediated mRNA decay pathway as described by Park et al [129]. GR with bound GC recruits PNRC2 and DCP1A together with UPF1 to the 5′ UTR of a target mRNA to form Complex I. HRSP12 and YBX1 are then recruited to form Complex II and mRNA decay is performed by exonucleases.…”

“…This research group investigated how GMD occurs. They reported that GMD is a distinct mRNA decay pathway that shares factors with other forms of RNA decay [128,129]. GMD depends on a number of proteins that have to be recruited to the mRNA.…”

“…PNRC2 and UPF1 are known to bind to each other to bring RNA helicase activity into the complex. Another pair of factors that are known for their ability to degrade mRNA are DCP1A, which promotes mRNA decapping by DCP1 activity, and HRSP12, an endoribonuclease that can attack mRNA [129]. Although exciting, GMD still needs to be confirmed by unbiased approaches such as genome-wide transcriptomic comparisons of nascent RNA and steady-state RNA which have the capacity to simultaneously report mRNA transcription and decay rates [130].…”