Planar Cell Polarity: Keeping Hairs Straight Is Not So Simple

Abstract

The fur on a cat's back, the scales on a fish, or the bristles on a fly are all beautifully organized, with a high degree of polarization in their surface organization. Great progress has been made in understanding how individual cell polarity is established, but our understanding of how cells coordinate their polarity in forming coherent tissues is still fragmentary. The organization of cells in the plane of the epithelium is known as planar cell polarity (PCP), and studies in the past decade have delineated a genetic pathway for the control of PCP. This review will first briefly review data from the Drosophila field, where PCP was first identified and genetically characterized, and then explore how vertebrate tissues become polarized during development.

Gpr125 modulates Dishevelled distribution and planar cell polarity signaling

“…Asymmetric localization of PCP components in polarized epithelia and protein interaction studies supports a model whereby PCP components interact in asymmetric membrane complexes spanning the juxtaposed cells to generate planar polarization (McNeill, 2010;Goodrich and Strutt, 2011). Recently, Dsh was shown to cluster PCP complexes into membrane subdomains in cells of Drosophila pupal wings , raising the possibility that clustering of asymmetric PCP complexes into membrane subdomains might provide a local self-enhancement mechanism that establishes and/or maintains planar polarity (Strutt , 2011).…”

“…This stereotyped asymmetric localization of Pk and Dvl on opposing anterior and posterior membranes has been observed in the neural plate and dorsal mesodermal cells undergoing C&E in zebrafish (Ciruna et al, 2006;Yin et al, 2008). Such molecular asymmetries are considered to be either a consequence of cell polarization or an essential step in the process of Wnt/PCP-mediated cell polarization (Simons and Mlodzik, 2008;McNeill, 2010;Goodrich and Strutt, 2011;Gray et al, 2011).…”

Adherens Junction: Molecular Architecture and Regulation

“…These include desmosomal cadherins (Wheeler et al 1991;Buxton and Magee 1992), protocadherins (Redies et al 2005;Morishita and Yagi 2007), Fat and Dachsous cadherins (Saburi and McNeill 2005;Tanoue and Takeichi 2005), and Flamingo/Celsr (Takeichi 2007) (see McNeill et al 2009). Among them, desmosomal cadherins are the closest to the classic cadherins, and desmosomes, in fact, are similar in appearance to AJs, though not identical from a number of aspects (Holthofer et al 2007) (see Green et al 2009;Delva et al 2009).…”

Wnt5aandWnt11regulate mammalian anterior-posterior axis elongation

“…The PCP pathway was initially identified in Drosophila melanogaster, where it controls the establishment of a polarity within an epithelial sheet perpendicular to apical-basal polarity. A group of core PCP components has been identified in Drosophila, and these are functionally conserved in vertebrates (Tree et al, 2002;Seifert and Mlodzik, 2007;McNeill, 2010). In vertebrates, PCP regulates CE of axial and paraxial mesodermal cells during axis elongation, and defects in PCP signaling result in a shortened and widened A-P axis (Greene et al, 1998;Keller, 2002;Wallingford et al, 2002;Ybot-Gonzalez et al, 2007;Roszko et al, 2009;Song et al, 2010;Mahaffey et al, 2013).…”