TY - JOUR TI - Contact localized β-actin translation drives epithelial adherens junction assembly DO - https://doi.org/doi:10.7282/T37S7QDX PY - 2014 AB - Adherens junctions are multi-protein adhesion complexes that anchor to the actin cytoskeleton at cell-cell contact sites to stimulate tissue assembly and thereby regulate barrier maintenance, epithelial tissue homeostasis, and embryonic development. Previously it was demonstrated that the mRNA for β-actin contains a nucleotide sequence in its 3’ UTR, called the zipcode, which is necessary for targeting and translational regulation of this transcript. The zipcode sequence is recognized by the translation regulator zipcode binding protein-1, ZBP1. Additionally, deleting zipcode sequences causes mislocalization of their mRNA transcript. Here we show mislocalizing β-actin’s monomer synthesis inhibits adherens junction assembly following epithelial cell-cell contact. Additionally, inhibiting RhoA and Src signaling, required for β-actin mRNA zipcode-mediated spatially regulated β-actin translation, prevents adherens junction assembly and significantly perturbs epithelial barrier integrity. In fact, TRITC-dextran barrier permeability significantly increases in epithelial cells expressing β-actin transcripts without the 3’ untranslated region (Δ3’UTR-β-actin) at steady state and in the hours post-contact compared to full-length expressing cells. Moreover, in full-length β-actin GFP (FL-β-actin GFP) expressing cells, β-actin mRNA zipcode antisense oligonucleotide masking of the zipcode sequence also perturbs barrier maintenance. Intriguingly, chemically inhibiting the signaling pathways required for β-actin mRNA localization and local translation (RhoA and Src) also perturbs epithelial barrier maintenance. Taken together, we demonstrate epithelial cell-cell contact stimulates E-cadherin mediated signaling to spatially regulate β-actin mRNA zipcode-dependent monomer synthesis thereby driving adherens junction assembly, cell, and tissue adhesion required for proper epithelial tissue function. KW - Biology KW - Actin KW - Cell adhesion molecules KW - Cell receptors LA - eng ER -