Different Endomembrane Trafficking Pathways Establish Apical and Basal Polarities
Ruixi Li1,2,3, Cecilia Rodriguez-Furlan1,2, Junqi Wang4
1Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, California 92521.
The Plant Cell
|December 25, 2016
Summary
A new compound, endosidin 16 (ES16), disrupts apical cell polarity in plants by inhibiting protein recycling and secretion. This discovery reveals a distinct endomembrane pathway essential for maintaining cell polarity.
Area of Science:
- Plant cell biology
- Molecular and cell biology
- Biochemistry
Background:
- The endomembrane system is crucial for cell signaling, polarity, and shape.
- While basal polarity mechanisms are understood, apical polarity maintenance is unclear.
Purpose of the Study:
- To identify mechanisms maintaining apical cell polarity in plants.
- To characterize the function of novel compounds affecting endomembrane trafficking.
Main Methods:
- Chemical genomics screen to identify inhibitors of apical polarity.
- Analysis of endomembrane trafficking and protein localization.
- Pharmacological and genetic validation of compound targets.
Main Results:
- Endosidin 16 (ES16) selectively perturbs apical plasma membrane proteins without affecting basal polarity.
- ES16 inhibits recycling and secretion of apical, lateral, and nonpolar proteins.
- ES16 action is mediated by RabA GTPases interacting with BIG clade ARF-GEFs.
Conclusions:
- ES16 defines a novel endomembrane sorting pathway.
- RabA GTPases and BIG clade ARF-GEFs regulate nonbasal trafficking.
- This pathway is essential for establishing and maintaining plant cell polarity.
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