Planar Cell Polarity (PCP)
Non-canonical Wnt pathway coordinating tissue-level cell orientation.
Overview
Planar cell polarity coordinates cell orientation within the plane of a tissue, perpendicular to the apical-basal axis. Core PCP proteins (Frizzled, Dishevelled, Van Gogh/Vangl, Prickle, Flamingo/Celsr, Diego/Ankrd6) form asymmetric complexes that propagate polarity information between cells. Downstream effectors include RhoA, Rac1, and JNK, controlling cytoskeletal rearrangements. PCP controls hair follicle orientation, cochlear hair cell alignment, and neural tube closure via convergent extension.
Cellular Location
Plasma membrane, cytoplasm
Clinical Significance
Neural tube defects (spina bifida, craniorachischisis) linked to PCP mutations; Vangl2 is the most studied PCP gene in vertebrates; regulates wound healing and cancer cell invasion.