Mouse Gata1 3'UTR modulates Gata1 levels to affect erythropoiesis

The 3' untranslated region (3'UTR) of mRNA is crucial for post-transcriptional gene regulation, primarily through miRNAs. However, the overall role of the Gata1 3'UTR in mammals remains unclear. In this study, we knocked out the Gata1 3'UTR and observed a defect in erythropoiesis in mutant mice, evidenced by macrocytic anemia at baseline. The deletion of the Gata1 3'UTR also caused deficiencies in erythropoiesis within fetal livers. Mechanistically, removing the Gata1 3'UTR destabilizes Gata1 mRNA, leading to decreased levels of Gata1 protein. This reduced stability results from the dissociation of AU-rich elements in the 3'UTR from a trans-acting factor called ELAV-like family 1 (ELAVL1). Specifically, we conducted an RNA pulldown assay followed by mass spectrometry to identify proteins that bind to the Gata1 3'UTR. Gene Ontology analysis revealed that Elavl1 is a binding partner across nearly all categories related to mRNA stabilization. Western blotting, RNA immunoprecipitation, and mutagenesis assays confirmed the direct interaction between the Gata1 3'UTR and Elavl1. Modulating Elavl1 activity or protein levels with the small molecule inhibitor dihydro-tanshinone-I, or through ectopic expression in erythroid cells, validated Elavl1 as a stabilizing factor for Gata1 mRNA. Our results highlight the important role of the Gata1 mRNA 3'UTR in erythroid development.