Zinc-finger RNA-binding protein that destabilizes several cytoplasmic AU-rich element (ARE)-containing mRNA transcripts by promoting their poly(A) tail removal or deadenylation, and hence provide a mechanism for attenuating protein synthesis (PubMed:10751406, PubMed:12748283). Acts as a 3'-untranslated region (UTR) ARE mRNA-binding adapter protein to communicate signaling events to the mRNA decay machinery (PubMed:12748283). Functions by recruiting the CCR4-NOT deadenylase complex and components of the cytoplasmic RNA decay machinery to the bound ARE-containing mRNAs, and hence promotes ARE-mediated mRNA deadenylation and decay processes (PubMed:12748283). Induces also the degradation of ARE-containing mRNAs even in absence of poly(A) tail (PubMed:11279239). Binds to 3'-UTR ARE of numerous mRNAs (PubMed:10751406). Positively regulates early adipogenesis by promoting ARE-mediated mRNA decay of immediate early genes (IEGs). Promotes ARE-mediated mRNA decay of mineralocorticoid receptor NR3C2 mRNA in response to hypertonic stress. Negatively regulates hematopoietic/erythroid cell differentiation by promoting ARE-mediated mRNA decay of the transcription factor STAT5B mRNA. Positively regulates monocyte/macrophage cell differentiation by promoting ARE-mediated mRNA decay of the cyclin-dependent kinase CDK6 mRNA. Promotes degradation of ARE-containing pluripotency-associated mRNAs in embryonic stem cells (ESCs), such as NANOG, through a fibroblast growth factor (FGF)-induced MAPK-dependent signaling pathway, and hence attenuates ESC self-renewal and positively regulates mesendoderm differentiation. May play a role in mediating pro-apoptotic effects in malignant B-cells by promoting ARE-mediated mRNA decay of BCL2 mRNA. In association with ZFP36L2 maintains quiescence on developing B lymphocytes by promoting ARE-mediated decay of several mRNAs encoding cell cycle regulators that help B cells progress through the cell cycle, and hence ensuring accurate variable-diversity-joining (VDJ) recombination and functional immune cell formation. Together with ZFP36L2 is also necessary for thymocyte development and prevention of T-cell acute lymphoblastic leukemia (T-ALL) transformation by promoting ARE-mediated mRNA decay of the oncogenic transcription factor NOTCH1 mRNA. Participates in the delivery of target ARE-mRNAs to processing bodies (PBs). In addition to its cytosolic mRNA-decay function, plays a role in the regulation of nuclear mRNA 3'-end processing; modulates mRNA 3'-end maturation efficiency of the DLL4 mRNA through binding with an ARE embedded in a weak noncanonical polyadenylation (poly(A)) signal in endothelial cells. Also involved in the regulation of stress granule (SG) and P-body (PB) formation and fusion. Plays a role in vasculogenesis and endocardial development. Plays a role in the regulation of keratinocyte proliferation, differentiation and apoptosis. Plays a role in myoblast cell differentiation (By similarity). Associates with the cytoplasmic CCR4-NOT deadenylase and RNA exosome complexes to trigger ARE-containing mRNA deadenylation and decay processes. Interacts with CNOT1. Interacts (via N-terminus) with CNOT6. Interacts with CNOT7; this interaction is inhibited in response to phorbol 12-myristate 13-acetate (PMA) treatment in a p38 MAPK-dependent manner. Interacts with DCP1A. Interacts (via N-terminus) with DCP2. Interacts (via N-terminus) with EXOSC2. Interacts with XRN1. Interacts (via phosphorylated form) with YWHAB; this interaction occurs in a protein kinase AKT1-dependent manner. Interacts (via phosphorylated form) with YWHAZ; this interaction occurs in a p38 MAPK- and AKT-signaling pathways. Shuttles between the nucleus and the cytoplasm in a XPO1/CRM1-dependent manner. Component of cytoplasmic stress granules. Localizes in processing bodies (PBs). Phosphorylated. Phosphorylated by RPS6KA1 at Ser-334 upon phorbol 12-myristate 13-acetate (PMA) treatment; this phosphorylation results in dissociation of the CCR4-NOT deadenylase complex and induces p38 MAPK-mediated stabilization of the low-density lipoprotein receptor LDLR mRNA. Phosphorylated by protein kinase AKT1 at Ser-92 and Ser-203 in response to insulin; these phosphorylations stabilize ZFP36L1, increase the association with 14-3-3 proteins and mediate ARE-containing mRNA stabilization. AKT1-mediated phosphorylation at Ser-92 does not impair ARE-containing RNA-binding. Phosphorylated at Ser-54, Ser-92 and Ser-203 by MAPKAPK2; these phosphorylations increase the association with 14-3-3 proteins and mediate ARE-containing mRNA stabilization in a protein kinase AKT1-independent manner. MAPKAPK2-mediated phosphorylations at Ser-54, Ser-92 and Ser-203 do not impair ARE-containing RNA-binding (By similarity). Phosphorylations increase the association with 14-3-3 proteins and mediate ARE-containing mRNA stabilization during early adipogenesis in a p38 MAPK- and AKT-dependent manner (By similarity). Phosphorylated by protein kinase AKT1 at Ser-92 (PubMed:15538381). Ubiquitinated. Ubiquitination leads to proteasomal degradation, a process inhibited by phosphorylations at Ser-90, Ser-92 and Ser-203.