Acts in a planar cell polarity (PCP) complex; polarization along the apical/basal axis of epithelial cells. PCP signaling in the wing disk requires the receptor fz and the cytoplasmic proteins dsh and pk. These act in a feedback loop leading to activation of the jnk cascade and subsequent polarized arrangement of hairs and bristles. Dgo and pk compete with one another for dsh binding, thereby modulating fz dsh activity and ensuring tight control over fz PCP signaling. Vang, stan and pk function together to regulate the establishment of tissue polarity in the adult eye (By similarity). Interacts with dsh; PET and LIM domains interact with dsh DEP domain, in wing cells. Interacts with Vang in photoreceptor cells (By similarity). Belongs to the prickle / espinas / testin family.