A bi-directional negative feedback loop govern the orientation of planar polarity in the drosophila wing

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Abstract/Contents

Abstract
Epithelial cells sometimes display polarity along the axis orthogonal to the apicobasal axis -- a phenomenon referred to as planar cell polarity (PCP). This polarization biases organization of the cytoskeleton, and is required for a range of fundamental processes including, but not limited to, oriented cell division, polarized function of cilia, and the control of collective cell migration events during development. Consequently, deregulation or dysfunction of PCP genes has been linked to disorders including deafness as a result of misorientation of inner ear cells, neural tube closure defects because of a failure to execute convergent & extension, and tumor invasiveness. Despite having identified some of the key proteins required to achieve PCP, much is still unknown about their molecular functions. Evolutionarily conserved proteins, known as the core PCP proteins, are distributed asymmetrically within wing epithelial cells and form complexes within the proximal or distal cortical domains. Here, we demonstrate that these diametrically opposed complexes participate in a bi-directional negative feedback loop that simultaneously produces their asymmetric distribution within cells and reinforces the orientation of polarity to neighbors by transmitting polarity information intercellularly. We found that one of the core PCP proteins, Prickle (Pk), is important for negative feedback as it is required to mediate the exclusion of distal and proximal complexes from the plasma membrane during acquisition of asymmetry. Moreover, we found that the level of Pk is regulated by the Cullin1 (Cul1)/SkpA/Supernumerary limbs (Slimb) E3 ubiquitin ligase complex. Our observations lead us to believe that loss of, or excess, Pk perturbs PCP signaling through the disruption of feedback. Ultimately, these results highlight an underlying molecular mechanism for the generation of planar polarity. Finally, the approaches presented in this monograph can further help elucidate the molecular functions of the other core PCP proteins.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2014
Issuance monographic
Language English

Creators/Contributors

Associated with Pierre-Louis, Gandhy
Associated with Stanford University, Department of Developmental Biology.
Primary advisor Axelrod, Jeffrey (Jeffrey David)
Thesis advisor Axelrod, Jeffrey (Jeffrey David)
Thesis advisor Fuller, Margaret
Thesis advisor Nusse, Roel, 1950-
Thesis advisor Simon, Michael, (Biology professor)
Advisor Fuller, Margaret
Advisor Nusse, Roel, 1950-
Advisor Simon, Michael, (Biology professor)

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Gandhy Pierre-Louis.
Note Submitted to the Department of Developmental Biology.
Thesis Thesis (Ph.D.)--Stanford University, 2014.
Location electronic resource

Access conditions

Copyright
© 2014 by Gandhy Pierre-Louis
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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