PT  - JOURNAL ARTICLE
AU  - Chun Wan J. Lai
AU  - Alexander V. Kolesnikov
AU  - Jeanne M. Frederick
AU  - Devon R. Blake
AU  - Li Jiang
AU  - Jubal S. Stewart
AU  - Ching-Kang Chen
AU  - Jeffery R. Barrow
AU  - Wolfgang Baehr
AU  - Vladimir J. Kefalov
AU  - Barry M. Willardson
TI  - Phosducin-Like Protein 1 is Essential for G-Protein Assembly and Signaling in Retinal Rod Photoreceptors
AID  - 10.1523/JNEUROSCI.5001-12.2013
DP  - 2013 May 01
TA  - The Journal of Neuroscience
PG  - 7941--7951
VI  - 33
IP  - 18
4099  - http://www.jneurosci.org/content/33/18/7941.short
4100  - http://www.jneurosci.org/content/33/18/7941.full
SO  - J. Neurosci.2013 May 01; 33
AB  - G-protein β subunits perform essential neuronal functions as part of G-protein βγ and Gβ5-regulators of G-protein signaling (RGS) complexes. Both Gβγ and Gβ5-RGS are obligate dimers that are thought to require the assistance of the cytosolic chaperonin CCT and a cochaperone, phosducin-like protein 1 (PhLP1) for dimer formation. To test this hypothesis in vivo, we deleted the Phlp1 gene in mouse (Mus musculus) retinal rod photoreceptor cells and measured the effects on G-protein biogenesis and visual signal transduction. In the PhLP1-depleted rods, Gβγ dimer formation was decreased 50-fold, resulting in a >10-fold decrease in light sensitivity. Moreover, a 20-fold reduction in Gβ5 and RGS9–1 expression was also observed, causing a 15-fold delay in the shutoff of light responses. These findings conclusively demonstrate in vivo that PhLP1 is required for the folding and assembly of both Gβγ and Gβ5-RGS9.