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Updated: Aug 25, 2025
07:07
Evaluation of Planar-Cell-Polarity Phenotypes in Ciliopathy Mouse Mutant Cochlea
Published on: February 21, 2016
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Rack1 regulates cellular patterning and polarity in the mouse cochlea
Dehong Yu1, Di Deng2, Binjun Chen3
1Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Ear Institute, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Department of Cell Biology, Emory University, Atlanta, GA, United States; Department of Otolaryngology, Emory University, Atlanta, GA, United States; Materdicine Lab, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China.
Experimental Cell Research
|October 17, 2022
Summary
Receptor for activated C kinase 1 (Rack1) is essential for hearing development in mice. Rack1 deficiency disrupts cochlear cell patterning and hair cell orientation by affecting E-cadherin at cell junctions.
Area of Science:
- Developmental biology
- Cell biology
- Genetics
Background:
- Receptor for activated C kinase 1 (Rack1) is a scaffolding protein involved in various cellular processes.
- Rack1 has been implicated in planar cell polarity (PCP) in other species but its molecular role is unclear.
- Rack1's function in mammalian development, particularly in hearing, is not well understood.
Purpose of the Study:
- To investigate the essential role of Rack1 in mammalian development.
- To elucidate the molecular mechanisms by which Rack1 regulates planar cell polarity (PCP) in the developing cochlea.
- To determine Rack1's impact on cellular junctions and hair cell development.
Main Methods:
- Conditional knockout of Rack1 in mice.
- Analysis of cochlear duct development and cellular patterning.
- Immunohistochemical analysis of E-cadherin expression.
- Microscopic examination of sensory hair cell orientation.
Main Results:
- Conditional knockout of Rack1 led to shortened cochlear ducts and defects in convergent extension.
- Rack1 deficiency resulted in misoriented cochlear hair cells.
- Rack1 was localized to the cellular cortices of sensory hair cells.
- E-cadherin expression was significantly reduced at cellular boundaries in Rack1-deficient cochleae.
Conclusions:
- Rack1 is essential for normal cochlear development and planar cell polarity (PCP) in mice.
- Rack1 plays a critical role in regulating E-cadherin levels at adherens junctions.
- These findings reveal a molecular mechanism for Rack1 in PCP signaling and hearing development.
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