Control of vertebrate core PCP protein localization and dynamics by Prickle2

Abstract

Planar cell polarity (PCP) is a ubiquitous property of animal tissues and is essential for morphogenesis and homeostasis. In most cases, this fundamental property is governed by a deeply conserved set of 'core PCP' proteins, which includes the transmembrane proteins Van Gogh-like (Vangl) and Frizzled (Fzd), as well as the cytoplasmic effectors Prickle (Pk) and Dishevelled (Dvl). Asymmetric localization of these proteins is thought to be central to their function, and understanding the dynamics of these proteins is an important challenge in developmental biology. Among the processes that are organized by the core PCP proteins is the directional beating of cilia, such as those in the vertebrate node, airway and brain. Here, we exploit the live imaging capabilities of Xenopus to chart the progressive asymmetric localization of fluorescent reporters of Dvl1, Pk2 and Vangl1 in a planar polarized ciliated epithelium. Using this system, we also characterize the influence of Pk2 on the asymmetric dynamics of Vangl1 at the cell cortex, and we define regions of Pk2 that control its own localization and those impacting Vangl1. Finally, our data reveal a striking uncoupling of Vangl1 and Dvl1 asymmetry. This study advances our understanding of conserved PCP protein functions and also establishes a rapid, tractable platform to facilitate future in vivo studies of vertebrate PCP protein dynamics.

Planar cell polarity in moving cells: think globally, act locally

“…With few exceptions, the relationship between core PCP components in vertebrate epithelial cells is the same as in flies, with Fzd and Dvl localizing together, opposite Vangl and Prickle (hereafter Pk) (Fig. 1B-D) (Butler and Wallingford, 2015;Chu and Sokol, 2016;Ciruna et al, 2006;Davey et al, 2016;Deans et al, 2007;Devenport et al, 2011;Hashimoto et al, 2010;Vladar et al, 2012;Yin et al, 2008). Altering the expression of Vang or Fz homologs mosaically in the frog skin or in the sensory epithelium of the chick ear disrupts the polarity of adjacent wild-type cells, suggesting that the molecular interactions between core PCP components that amplify and maintain their asymmetric localization are conserved between fly and vertebrate epithelia (Mitchell et al, 2009;Sienknecht et al, 2011).…”

“…In both multiciliated (dark gray spots) and surrounding cells, endogenous Vangl1, Pk2 and GFP-Pk1 (red) localize to the distal surface and GFP-Fzd3/6 and GFP-Dvl1/3 localize to the proximal surface. (D) Xenopus epidermal cells (Butler and Wallingford, 2015). In both multiciliated and surrounding cells, Dvl1:GFP localizes to the dorsal side whereas RFP-Pk1/2 and RFP-Vangl1 localize to the ventral side of the same cells.…”

Multiciliated Cells in Animals

“…Intriguingly, this distribution is reversed compared with that of mouse MCCs: Vangl1 and Pk2 localize downstream from flow, whereas Dvl1 and Fzd6 localize upstream of flow (Fig. 4) (Butler and Wallingford 2015).…”

“…In Xenopus, expression of Vangl2 (Butler and Wallingford 2015). When wt MCCs intercalate within a PCP-deficient outer epidermal layer in grafting experiments, intracellular basal body (BB) orientation is coordinated but improperly aligned with tissue polarity.…”

Prickle1 promotes focal adhesion disassembly in cooperation with CLASP-LL5β complex in migrating cells

“…Therefore, Prickle1 might have previously unknown functions in regulating polarity and migration in non-neuronal mammalian cells. Xenopus Prickle2 in multiciliated epithelial cells controls the asymmetric localization of a subset of core PCP family proteins (Butler and Wallingford, 2015). The underlying mechanism of Prickle-mediated nonneuronal polarity and migration, however, remains to be defined.…”