Abstract |
During plant cell morphogenesis, signal transduction and cytoskeletal dynamics interact to locally organize the cytoplasm and define the geometry of cell expansion. The WAVE/ SCAR (for WASP family verprolin homologous/suppressor of cyclic AMP receptor) regulatory complex (W/SRC) is an evolutionarily conserved heteromeric protein complex. Within the plant kingdom W/SRC is a broadly used effector that converts Rho-of-Plants (ROP)/Rac small GTPase signals into Actin-Related Protein2/3 and actin-dependent growth responses. Although the components and biochemistry of the W/SRC pathway are well understood, a basic understanding of how cells partition W/SRC into active and inactive pools is lacking. In this paper, we report that the endoplasmic reticulum (ER) is an important organelle for W/SRC regulation. We determined that a large intracellular pool of the core W/SRC subunit NAP1, like the known positive regulator of W/SRC, the DOCK family guanine nucleotide-exchange factor SPIKE1 (SPK1), localizes to the surface of the ER. The ER-associated NAP1 is inactive because it displays little colocalization with the actin network, and ER localization requires neither activating signals from SPK1 nor a physical association with its W/SRC-binding partner, SRA1. Our results indicate that in Arabidopsis (Arabidopsis thaliana) leaf pavement cells and trichomes, the ER is a reservoir for W/SRC signaling and may have a key role in the early steps of W/SRC assembly and/or activation.
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Authors | Chunhua Zhang, Eileen Mallery, Sara Reagan, Vitaly P Boyko, Simeon O Kotchoni, Daniel B Szymanski |
Journal | Plant physiology
(Plant Physiol)
Vol. 162
Issue 2
Pg. 689-706
(Jun 2013)
ISSN: 1532-2548 [Electronic] United States |
PMID | 23613272
(Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Actins
- Arabidopsis Proteins
- DIS3 protein, Arabidopsis
- Multiprotein Complexes
- SPIKE1 protein, Arabidopsis
- Adenosine Triphosphatases
- NAP1 protein, Arabidopsis
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Topics |
- Actins
(metabolism)
- Adenosine Triphosphatases
(genetics, metabolism)
- Arabidopsis
(genetics, metabolism)
- Arabidopsis Proteins
(genetics, metabolism)
- Endoplasmic Reticulum
(genetics, metabolism)
- Intracellular Membranes
(metabolism)
- Multiprotein Complexes
(metabolism)
- Plant Leaves
(genetics, metabolism)
- Plants, Genetically Modified
- Signal Transduction
- Trichomes
(metabolism)
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