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Adducins regulate remodeling of intercellular junctions in model human epithelia
Author(s) -
Ivanov Andrei I,
Naydenov Nayden G
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.348.3
Subject(s) - adherens junction , microbiology and biotechnology , spectrin , tight junction , cytoskeleton , downregulation and upregulation , cell junction , actin cytoskeleton , actin , chemistry , intracellular , cadherin , biology , cell , biochemistry , gene
Epithelial adherens junctions (AJs) and tight junctions (TJs) are dynamic structures readily undergoing disintegration and reassembly. Remodeling of AJs and TJs depends on orchestrated dynamics of the plasma membrane and the actin cytoskeleton, which implicates the membrane/cytoskeleton interface in junctional regulation. Spectrin‐adducin polymers link the plasma membrane to the actin cytoskeleton. We investigated roles of adducin in the remodeling of epithelial junctions. We used SK‐CO15 human colonic and HPAF‐II human pancreatic epithelial cells, which possess well‐formed AJs and TJs and express α‐ and γ isoforms of adducin. Both adducins colocalized with E‐cadherin and β‐catenin at mature and newly‐assembled AJs. siRNA‐mediated downregulation of α‐ and γ‐adducin expression in SK‐CO15 cells attenuated AJ reformation without affecting TJ assembly. Depletion of adducins decreased protein level of βII spectrin and dewnregulation of βII spectrin mimicked effects of adducins knock‐down on AJ reassembly. In HPAF‐II cell monolayers, disruption of apical junctions induced by phorbol ester was paralleled by phophorylation of adducins and their disappearance from intercellular contacts. Downregulation of α‐ and γ‐adducins accelerated phorbol ester‐induced AJ disassembly. These finding suggest novel roles for adducins in the establishment and stabilization of epithelial adherens junctions.