ZFP36L1 and ZFP36L2 control LDLR mRNA stability via the ERK-RSK pathway.
Bottom Line: 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.These results indicate that ZFP36L1 and ZFP36L2 regulate LDLR protein levels downstream of ERK.
Affiliation: Molecular Profiling Research Center for Drug Discovery (molprof), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo 135-0064, Japan Galaxy Pharma Inc., Akita 010-0951, Japan.Show MeSH
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Mentions: ZFP36L1 and ZFP36L2 are known as proteins that bind to a certain type of ARE that contains the sequence UAUUUAUU, causing destabilization of target mRNAs. The LDLR mRNA 3′-UTR contains three AREs (ARE1–3) (4); ARE1 and ARE2 are comprised of the UAUUUAUU sequence. We investigated the region responsible for LDLR mRNA instability and PMA-mediated stabilization (PMA is an activator of ERK) in an ActD chase experiment. After transfection of 293T cells with the reporter constructs, RFP-LDLR-3′-UTR-ARE1–3, RFP-LDLR-3′-UTR-ARE2–3 or RFP-LDLR-3′-UTR-ARE1, we examined the stability of the reporter mRNA and the effect of PMA on stability using quantitative reverse-transcription (RT)-PCR (qPCR) analysis. We also calculated the half-life of each RFP-reporter mRNA (Figure 2A and B). We found that the ARE1-containing region is not only responsible for LDLR mRNA instability, but is also responsible for PMA-mediated stabilization of LDLR mRNA.
Affiliation: Molecular Profiling Research Center for Drug Discovery (molprof), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo 135-0064, Japan Galaxy Pharma Inc., Akita 010-0951, Japan.