A Presenilin-2-ARF4 trafficking axis modulates Notch signaling during epidermal differentiation

作者:Ezratty Ellen J; Pasolli H Amalia; Fuchs Elaine*
来源:The Journal of Cell Biology, 2016, 214(1): 89-101.
DOI:10.1083/jcb.201508082

摘要

How primary cilia impact epidermal growth and differentiation during embryogenesis is poorly understood. Here, we show that during skin development, Notch signaling occurs within the ciliated, differentiating cells of the first few supra basal epidermal layers. Moreover, both Notch signaling and cilia disappear in the upper layers, where key ciliary proteins distribute to cell-cell borders. Extending this correlation, we find that Presenilin-2 localizes to basal bodies/cilia through a conserved VxPx motif. When this motif is mutated, a GFP-tagged Presenilin-2 still localizes to intercellular borders, but basal body localization is lost. Notably, in contrast to wild type, this mutant fails to rescue epidermal differentiation defects seen upon Psen 1 and 2 knockdown. Screening components implicated in ciliary targeting and polarized exocytosis, we provide evidence that the small GTPase ARM is required for Presenilin basal body localization, Notch signaling, and subsequent epidermal differentiation. Collectively, our findings raise the possibility that ARF4-dependent polarized exocytosis acts through the basal body ciliary complex to spatially regulate Notch signaling during epidermal differentiation.

  • 出版日期2016-7-4