Anchoring of protein kinase A-regulatory subunit IIalpha to subapically positioned centrosomes mediates apical bile canalicular lumen development in response to oncostatin M but not cAMP

Mol Biol Cell. 2007 Jul;18(7):2745-54. doi: 10.1091/mbc.e06-08-0732. Epub 2007 May 9.

Abstract

Oncostatin M and cAMP signaling stimulate apical surface-directed membrane trafficking and apical lumen development in hepatocytes, both in a protein kinase A (PKA)-dependent manner. Here, we show that oncostatin M, but not cAMP, promotes the A-kinase anchoring protein (AKAP)-dependent anchoring of the PKA regulatory subunit (R)IIalpha to subapical centrosomes and that this requires extracellular signal-regulated kinase 2 activation. Stable expression of the RII-displacing peptide AKAP-IS, but not a scrambled peptide, inhibits the association of RIIalpha with centrosomal AKAPs and results in the repositioning of the centrosome from a subapical to a perinuclear location. Concomitantly, common endosomes, but not apical recycling endosomes, are repositioned from a subapical to a perinuclear location, without significant effects on constitutive or oncostatin M-stimulated basolateral-to-apical transcytosis. Importantly, however, the expression of the AKAP-IS peptide completely blocks oncostatin M-, but not cAMP-stimulated apical lumen development. Together, the data suggest that centrosomal anchoring of RIIalpha and the interrelated subapical positioning of these centrosomes is required for oncostatin M-, but not cAMP-mediated, bile canalicular lumen development in a manner that is uncoupled from oncostatin M-stimulated apical lumen-directed membrane trafficking. The results also imply that multiple PKA-mediated signaling pathways control apical lumen development and that subapical centrosome positioning is important in some of these pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / pharmacology
  • Bile Canaliculi / drug effects
  • Bile Canaliculi / enzymology*
  • Bucladesine / pharmacology*
  • Cell Line, Tumor
  • Cell Membrane / drug effects
  • Cell Membrane / enzymology
  • Cell Polarity / drug effects*
  • Centrosome / drug effects*
  • Centrosome / enzymology*
  • Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit
  • Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Endocytosis / drug effects
  • Endosomes / drug effects
  • Humans
  • Oncostatin M / pharmacology*
  • Protein Binding / drug effects
  • Subcellular Fractions / drug effects

Substances

  • Adaptor Proteins, Signal Transducing
  • Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit
  • PRKAR2A protein, human
  • Oncostatin M
  • Bucladesine
  • Cyclic AMP-Dependent Protein Kinases