A dynamically regulated 14-3-3, Slob, and Slowpoke potassium channel complex in Drosophila presynaptic nerve terminals

Neuron. 1999 Apr;22(4):809-18. doi: 10.1016/s0896-6273(00)80739-4.


Slob is a novel protein that binds to the carboxy-terminal domain of the Drosophila Slowpoke (dSlo) calcium-dependent potassium (K(Ca)) channel. A yeast two-hybrid screen with Slob as bait identifies the zeta isoform of 14-3-3 as a Slob-binding protein. Coimmunoprecipitation experiments from Drosophila heads and transfected cells confirm that 14-3-3 interacts with dSlo via Slob. All three proteins are colocalized presynaptically at Drosophila neuromuscular junctions. Two serine residues in Slob are required for 14-3-3 binding, and the binding is dynamically regulated in Drosophila by calcium/calmodulin-dependent kinase II (CaMKII) phosphorylation. 14-3-3 coexpression dramatically alters dSlo channel properties when wild-type Slob is present but not when a double serine mutant Slob that is incapable of binding 14-3-3 is present. The results provide evidence for a dSlo/Slob/14-3-3 regulatory protein complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins
  • Animals
  • Calcium / physiology
  • Drosophila / physiology*
  • Drosophila Proteins*
  • Hybridization, Genetic
  • Insect Proteins / physiology
  • Nerve Tissue Proteins / physiology
  • Neuromuscular Junction / physiology
  • Phosphorylation
  • Potassium Channels / physiology
  • Presynaptic Terminals / physiology
  • Proteins / physiology
  • Tyrosine 3-Monooxygenase*


  • 14-3-3 Proteins
  • Drosophila Proteins
  • Insect Proteins
  • Nerve Tissue Proteins
  • Potassium Channels
  • Proteins
  • Slob protein, Drosophila
  • Tyrosine 3-Monooxygenase
  • Calcium