Developmental patterning function of GNOM ARF-GEF mediated from the cell periphery
Maciek Adamowski1,2, Ivana Matijević1, Jiří Friml1
1Institute of Science and Technology Austria, Klosterneuburg, Austria.
Elife
|February 21, 2024
Summary
The Guanine nucleotide Exchange Factor GNOM (GN) functions at the cell periphery, not the Golgi, to regulate plant development. This study clarifies GNOM
Area of Science:
- Plant cell biology
- Molecular plant science
- Developmental biology
Background:
- GNOM (GN) is a key regulator of plant trafficking, essential for development.
- Existing models place GN at the Golgi apparatus (GA) and plasma membrane (PM).
- The precise mechanism of GN's unique developmental role, distinct from GNL1, is unclear.
Purpose of the Study:
- To elucidate the mechanistic basis of GN's unique developmental functions.
- To determine the specific localization and function of GN compared to GNL1.
- To investigate the role of the cell periphery in GN's developmental activity.
Main Methods:
- Localization studies of GN and GNL1 in plant cells.
- Analysis of GN function in gn knockouts and a functional mutant (GNfewerroots).
- Investigation of GN and GNL1 behavior upon Brefeldin A treatment.
- Functional analysis of GN-GNL1 chimeric proteins.
Main Results:
- GN, unlike GNL1, localizes to long-lived structures at the cell periphery, not clathrin-coated pits.
- gn knockouts show normal clathrin-mediated endocytosis and secretion.
- The cell periphery appears to be the primary site for GN's developmental function, as indicated by the GNfewerroots mutant.
- GN, but not GNL1, relocates to the PM on exocytic vesicles after Brefeldin A treatment.
- All GN domains contribute to its specific function, with partial redundancy.
Conclusions:
- GNOM's primary site of action for developmental functions is the cell periphery, not the Golgi apparatus.
- GNOM's localization and function are distinct from its homolog GNL1.
- This study provides critical insights into the molecular mechanisms underlying GNOM's unique roles in plant development.
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