Celsr1 And Celsr2 Exhibit Distinct Adhesive Interactions And Contributions To Planar Cell Polarity

This document reports on the distinct roles of Celsr1 and Celsr2 proteins in planar cell polarity (PCP) in the skin, particularly in the alignment of hair follicles. Using CRISPR/Cas9-targeted knockout mouse lines, the study found that Celsr1 is the primary contributor to epidermal PCP, as its removal resulted in the loss of PCP protein asymmetry and hair follicle polarization. In contrast, the loss of Celsr2 did not affect epidermal PCP, and the combined elimination of both Celsr1 and Celsr2 only slightly worsened the Celsr1 knockout phenotype. The study also discovered that Celsr1 is more stably enriched at cellular junctions compared to Celsr2, which is less efficiently recruited and immobilized at these junctions. Despite both proteins being able to interact with core PCP proteins Vangl2 and Fz6, the difference in their homophilic adhesion properties may explain their differential involvement in epidermal PCP.