The mechanical stability of epithelial cells, which protect organisms from harmful external factors, is maintained by hemidesmosomes via the interaction between plectin 1a (P1a) and integrin α6β4. Binding of calcium-calmodulin (Ca(2+)-CaM) to P1a together with phosphorylation of integrin β4 disrupts this complex, resulting in disassembly of hemidesmosomes. We present structures of the P1a actin binding domain either in complex with the N-ter lobe of Ca(2+)-CaM or with the first pair of integrin β4 fibronectin domains. Ca(2+)-CaM binds to the N-ter isoform-specific tail of P1a in a unique manner, via its N-ter lobe in an extended conformation. Structural, cell biology, and biochemical studies suggest the following model: binding of Ca(2+)-CaM to an intrinsically disordered N-ter segment of plectin converts it to an α helix, which repositions calmodulin to displace integrin β4 by steric repulsion. This model could serve as a blueprint for studies aimed at understanding how Ca(2+)-CaM or EF-hand motifs regulate F-actin-based cytoskeleton.
- MeSH
- hemidesmozomy chemie MeSH
- hydrofobní a hydrofilní interakce MeSH
- integrin beta4 chemie MeSH
- interakční proteinové domény a motivy MeSH
- kalmodulin chemie MeSH
- krysa rodu rattus MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- molekulární modely MeSH
- molekulární sekvence - údaje MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- plektin chemie MeSH
- sekvence aminokyselin MeSH
- terciární struktura proteinů MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
