ZFP36L1 and ZFP36L2 control LDLR mRNA stability via the ERK–RSK pathway

Abstract

Low-density lipoprotein receptor (LDLR) mRNA is unstable, but is stabilized upon extracellular signal-regulated kinase (ERK) activation, possibly through the binding of certain proteins to the LDLR mRNA 3′-untranslated region (UTR), although the detailed mechanism underlying this stability control is unclear. Here, using a proteomic approach, we show that proteins ZFP36L1 and ZFP36L2 specifically bind to the 3′-UTR of LDLR mRNA and recruit the CCR4-NOT-deadenylase complex, resulting in mRNA destabilization. We also show that the C-terminal regions of ZFP36L1 and ZFP36L2 are directly phosphorylated by p90 ribosomal S6 kinase, a kinase downstream of ERK, resulting in dissociation of the CCR4-NOT-deadenylase complex and stabilization of LDLR mRNA. We further demonstrate that targeted disruption of the interaction between LDLR mRNA and ZFP36L1 and ZFP36L2 using antisense oligonucleotides results in upregulation of LDLR mRNA and protein. These results indicate that ZFP36L1 and ZFP36L2 regulate LDLR protein levels downstream of ERK. Our results also show the usefulness of our method for identifying critical regulators of specific RNAs and the potency of antisense oligonucleotide-based therapeutics.

Resolving the complexity of vitellogenins and their receptors in the tetraploid Atlantic salmon (Salmo salar): Ancient origin of the phosvitin‐less VtgC in chondrichthyean fishes

“…The two oocyte VtgRs are also dominated by splice variants lacking the O ‐linked sugar domain, which hinders proteolytic cleavage of the extracellular domain in mammalian LDLRs (Kozarsky, Kingsley, & Krieger, ; Magrané, Casaroli‐Marano, Reina, Gåfvels, & Vilaró, ). Knowledge about the stability of the vtgr transcripts is lacking, although mRNA stabilization through AU‐rich elements, as reported for ldlr mRNAs (Adachi et al, ; Li et al, ), may be insufficient to maintain the oocyte receptors for an extended period. Further studies are therefore needed to clarify the molecular mechanisms underlying the coordinated increase in the hepatic synthesis and ovarian uptake of Vtgs during vitellogenesis.…”

Codon bias confers stability to humanmRNAs

“…To identify RBPs that were either bound to transcripts bearing high or low optimality, we performed a ribonucleoprotein immunoprecipitation-based approach termed ISRIM (In vitro Specificity-based RNA Regulatory protein Identification Method) [41]. To identify RBPs that were either bound to transcripts bearing high or low optimality, we performed a ribonucleoprotein immunoprecipitation-based approach termed ISRIM (In vitro Specificity-based RNA Regulatory protein Identification Method) [41].…”

“…Purification and analysis of RNA-binding proteins Purification and analysis of RNA-binding protein (RBP) were carried out as described [41] with some modifications. Briefly, HEK293T cells were lysed with lysis buffer [10 mM HEPES (pH 7.5), 150 mM NaCl, 50 mM NaF, 1 mM Na 3 VO 4 , 5 lg/ml leupeptin, 5 lg ml aprotinin, 3 lg/ml pepstatin A, 1 mM phenylmethylsulfonyl fluoride (PMSF), and 1 mg/ml digitonin] and cleared by centrifugation.…”

The control of inflammation via the phosphorylation and dephosphorylation of tristetraprolin: a tale of two phosphatases

“…Regulation of function via phosphorylation of the C-terminus may therefore have been a property of the ancestral ZFP36 protein. In the cases of ZFP36L1 and ZFP36L2, phosphorylation can be mediated by p90 ribosomal S6 kinase, which is downstream of ERK [140]. The emerging picture of the relationship between kinases and ZFP36 family members appears increasingly complex, as individual phospho-acceptor sites may be targeted by more than one kinase pathway, and more than one family member may be subjected to phosphorylation in a given cell type.…”