Gbeta5 is required for normal light responses and morphology of retinal ON-bipolar cells

J Neurosci. 2007 Dec 19;27(51):14199-204. doi: 10.1523/JNEUROSCI.4934-07.2007.


Gbeta5 exists as two splice variants, Gbeta5-S and Gbeta5-L, which interact with and stabilize the R7 members of the regulators of G-protein signaling (RGSs): RGS6, RGS7, RGS9, and RGS11. Although the role of Gbeta5-L and RGS9-1 is established in photoreceptors, the physiological functions of Gbeta5-S and other R7 RGS proteins remain unclear. We found that the electroretinogram of Gbeta5-/- mice lacks the b-wave component and that Gbeta5-S and RGS11 colocalize with Go alpha at the tips of the ON-bipolar cell dendrites. Unexpectedly, we found a significant reduction in the number of synaptic triads in the outer plexiform layer (OPL) of the Gbeta5-/- mice, which is evident at postnatal day 14. Transgenic expression of Gbeta5-L in rods failed to rescue the b-wave or the OPL defects. These results indicate that Gbeta5-S is indispensable for OPL integrity and normal light responses of the retina.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Dark Adaptation / genetics
  • Dark Adaptation / physiology*
  • GTP-Binding Protein beta Subunits / deficiency
  • GTP-Binding Protein beta Subunits / genetics
  • GTP-Binding Protein beta Subunits / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Transgenic
  • Photic Stimulation / methods
  • Retina / cytology
  • Retina / physiology
  • Retinal Bipolar Cells / cytology*
  • Retinal Bipolar Cells / physiology*


  • GTP-Binding Protein beta Subunits
  • Gnb5 protein, mouse