Devon Blake, Brigham Young University
Chemistry and Biochemistry
G proteins play a vital role in cellular signaling. It has recently been shown that the nascent G polypeptide requires the assistance of phosducin-like protein 1 (PhLP1) for proper folding and formation of the G beta gamma dimer. This mechanism is derived from cell culture experiments and structural data, but until now had yet to be tested in vivo. We tested PhLP1 function in vivo using retinal rod photoreceptor-specific PhLP1 conditional knockout mice. Electroretinogram analyses of these mice showed a dramatic decrease in light sensitivity of rod photoreceptors. Consistent with this finding, the expression of all subunits of the photoreceptor G protein was reduced by 80%. This decrease was reflected in a similar decrease in the amount of G beta gamma dimers. All of these in vivo results are consistent with the hypothesis that PhLP1 is required for G beta gamma assembly and G protein signaling.