# Long-range coordination of planar polarity

> **NIH NIH R35** · UNIVERSITY OF MINNESOTA · 2024 · $368,273

## Abstract

Project Summary
The highly conserved Planar Cell Polarity (PCP) pathway is essential for cells to communicate directional
information between neighboring cells to drive collective cell movements and oriented cell behaviors during
embryonic development. Disruptions in PCP signaling lead to severe developmental disorders including
congenital heart defects, neural tube closure defects, and shortened body axes. The core PCP proteins are
transmembrane proteins that asymmetrically polarize to opposite sides of the cell. Extracellularly, the proteins
form an asymmetric bridge that directly couples the polarity of one cell to its adjacent neighbors. In this way, the
PCP proteins self-organize to coordinate cell polarity at the local level. A hallmark of PCP polarity, however, is
its tissue-wide coordination, spanning hundreds or thousands of cells across great distances. The self-organizing
properties of the core pathway alone cannot account for this long-range coordination as self-organization could
occur spontaneously in any direction. Further, modeling has shown that self-organization can only propagate
locally, resulting in a swirling pattern of PCP polarity rather than tissue-level coordination. For this reason, the
PCP field has come to a consensus that ‘directional cues’ are key missing factors that must link the PCP axis to
the tissue axis. Directional cues are thought to act in a gradient across a tissue where they bias the distribution
of the PCP proteins along the same axis by regulating their trafficking, stability, or turnover. Despite a general
consensus on how directional cues could pattern PCP organization, the identities of these cues remain elusive.
As such, the mechanism of their action cannot be interrogated. A major challenge in identifying directional cues
is that they are also required for tissue growth and differentiation. Thus, the tissue of interest becomes
compromised in the absence of the cue, making it difficult to investigate the cue’s role in organizing PCP in
isolation. Epidermal tissues provide a striking readout of planar polarity in their uniform alignment of bristles,
scales, fur, and feathers across an animal’s body. Remarkably, spontaneous mutations in small mammals and
birds have produced animals with region-specific misorientation of epidermal polarity. From these phenotypes,
we hypothesize that the skin is compartmentalized into region-specific domains that require multiple directional
cues to coordinate polarity across the tissue. Further, the fact that the skin is morphologically normal under these
conditions despite the polarity defects demonstrates that the skin can be leveraged as a model system to
interrogate directional cues. Our long-term goal is to identify and study the directional cues that pattern PCP
across the mouse epidermis to reveal mechanisms that coordinate long-range polarity. By using natural variants
and taking a candidate approach, we will identify and characterize directional cues and will ...

## Key facts

- **NIH application ID:** 10941502
- **Project number:** 1R35GM155344-01
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** Maureen Patricia Cetera
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $368,273
- **Award type:** 1
- **Project period:** 2024-07-01 → 2029-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10941502

## Citation

> US National Institutes of Health, RePORTER application 10941502, Long-range coordination of planar polarity (1R35GM155344-01). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10941502. Licensed CC0.

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