Spatial and temporal analysis of PCP protein dynamics during neural tube closure

TLDR

Planar cell polarity (PCP) orchestrates convergent extension and axis elongation in vertebrates, yet the dynamics of asymmetric PCP protein localization during this process remain poorly understood. Using quantitative live imaging, the study simultaneously tracked cell intercalation and PCP protein dynamics in the Xenopus laevis neural plate epithelium. The authors found that asymmetric PCP enrichment and its turnover rates tightly correlated with actomyosin‑driven contractile behavior of cell‑cell junctions, and that disrupting PCP signaling abolished these relationships, revealing a dynamic link between PCP localization, actomyosin assembly, and polarized junction shrinking during neural tube closure.

Abstract

Planar cell polarity (PCP) controls convergent extension and axis elongation in all vertebrates. Although asymmetric localization of PCP proteins is central to their function, we understand little about PCP protein localization during convergent extension. Here, we use quantitative live imaging to simultaneously monitor cell intercalation behaviors and PCP protein dynamics in the Xenopus laevis neural plate epithelium. We observed asymmetric enrichment of PCP proteins, but more interestingly, we observed tight correlation of PCP protein enrichment with actomyosin-driven contractile behavior of cell-cell junctions. Moreover, we found that the turnover rates of junctional PCP proteins also correlated with the contractile behavior of individual junctions. All these dynamic relationships were disrupted when PCP signaling was manipulated. Together, these results provide a dynamic and quantitative view of PCP protein localization during convergent extension and suggest a complex and intimate link between the dynamic localization of core PCP proteins, actomyosin assembly, and polarized junction shrinking during cell intercalation in the closing vertebrate neural tube.