A Role of myosin Vb and Rab11-FIP2 in the aquaporin-2 shuttle

Traffic. 2007 Feb;8(2):110-23. doi: 10.1111/j.1600-0854.2006.00508.x. Epub 2006 Dec 6.

Abstract

Arginine-vasopressin (AVP) regulates water reabsorption in renal collecting duct principal cells. Its binding to Gs-coupled vasopressin V2 receptors increases cyclic AMP (cAMP) and subsequently elicits the redistribution of the water channel aquaporin-2 (AQP2) from intracellular vesicles into the plasma membrane (AQP2 shuttle), thereby facilitating water reabsorption from primary urine. The AQP2 shuttle is a paradigm for cAMP-dependent exocytic processes. Using sections of rat kidney, the AQP2-expressing cell line CD8, and primary principal cells, we studied the role of the motor protein myosin Vb, its vesicular receptor Rab11, and the myosin Vb- and Rab11-binding protein Rab11-FIP2 in the AQP2 shuttle. Myosin Vb colocalized with AQP2 intracellularly in resting and at the plasma membrane in AVP-treated cells. Rab11 was found on AQP2-bearing vesicles. A dominant-negative myosin Vb tail construct and Rab11-FIP2 lacking the C2 domain (Rab11-FIP2-DeltaC2), which disrupt recycling, caused condensation of AQP2 in a Rab11-positive compartment and abolished the AQP2 shuttle. This effect was dependent on binding of myosin Vb tail and Rab11-FIP2-DeltaC2 to Rab11. In summary, we identified myosin Vb as a motor protein involved in AQP2 recycling and show that myosin Vb- and Rab11-FIP2-dependent recycling of AQP2 is an integral part of the AQP2 shuttle.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aquaporin 2 / biosynthesis
  • Aquaporin 2 / metabolism*
  • Carrier Proteins / biosynthesis
  • Carrier Proteins / physiology*
  • Cell Line
  • Cell Membrane / metabolism
  • Humans
  • Immunohistochemistry
  • Immunoprecipitation
  • Kidney / cytology
  • Kidney / metabolism*
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / physiology*
  • Myosin Heavy Chains / biosynthesis
  • Myosin Heavy Chains / physiology*
  • Myosin Type V / biosynthesis
  • Myosin Type V / physiology*
  • Myosins / biosynthesis
  • Myosins / physiology*
  • Protein Binding
  • Protein Transport
  • Rats
  • Recombinant Fusion Proteins / metabolism
  • Transfection
  • rab GTP-Binding Proteins

Substances

  • AQP2 protein, human
  • Aqp2 protein, rat
  • Aquaporin 2
  • Carrier Proteins
  • MYO5B protein, human
  • Membrane Proteins
  • Myo5b protein, rat
  • Recombinant Fusion Proteins
  • Myosin Type V
  • Myosin Heavy Chains
  • Myosins
  • RAB11FIP2 protein, human
  • rab GTP-Binding Proteins