Fig. 8: Restoring Coronin 7 abundance in Ubr4-deficient SCN neurons rescues VIP trafficking and promotes desynchronized behavior under chronic jetlag.

a TEM images showing the morphology of Golgi cisternae in the SCN of control and Ubr4 cKO mice. Scale bar, 500 nm. b Cisternae width of Golgi stacks in SCN tissues. Each symbol represents data from a single cell; symbol type (circle, diamond) denotes data from different animals. n = 20 control and 33 Ubr4 cKO cells from 2 mice (per genotype). ***p = 0.0002, two-tailed unpaired t test. c, e Photomicrographs of Ubr4^fl/fl SCN neurons that were co-transduced with AAVs expressing VIP along with either Cre-eGFP (CRE) or GFP (c). In e, cells were transduced with a third AAV construct expressing either mCherry or CRN7-mCherry, in addition to the Cre- and VIP-expressing AAVs used in c. Neurons were immunostained for VIP (magenta), GM130 (gray), GFP or CRE (green), and MAP2 or mCherry (cyan). Scale bar, 10 μm. d, f Ratio of VIP abundance in the Golgi relative to the rest of the soma for the experiments shown in c and e. n = 50 GFP, 49 CRE, 45 CRE mCherry, 40 CRE CRN7-mCherry. ***p < 0.0001, two-tailed Mann–Whitney U test. g Actograms showing wheel-running activities of Ubr4 cKO mice subjected to chronic jetlag (ChrA^6/2) following SCN injections of AAVs expressing mCherry or CRN7-mCherry. h Percentage of mice displaying “entrained” (one rhythm, ~21 h period) or “desynchronized” (two rhythms, ~21 and ~24 h periods) behavior under the ChrA^6/2 schedule. n = 9 Ubr4 cKO mCherry and 8 Ubr4 cKO CRN7-mCherry. *p = 0.0153, two-sided chi-square test. Values represent mean ± SEM (b, d, f) or percent (h). “n” represents the number of cells (b, d, f) or the number of mice (h).