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Post-Golgi trafficking of rice storage proteins requires the small GTPase Rab7 activation complex MON1–CCZ1
- Source :
- Plant Physiol
- Publication Year :
- 2021
- Publisher :
- Oxford University Press (OUP), 2021.
-
Abstract
- Protein storage vacuoles (PSVs) are unique organelles that accumulate storage proteins in plant seeds. Although morphological evidence points to the existence of multiple PSV-trafficking pathways for storage protein targeting, the molecular mechanisms that regulate these processes remain mostly unknown. Here, we report the functional characterization of the rice (Oryza sativa) glutelin precursor accumulation7 (gpa7) mutant, which over-accumulates 57-kDa glutelin precursors in dry seeds. Cytological and immunocytochemistry studies revealed that the gpa7 mutant exhibits abnormal accumulation of storage prevacuolar compartment-like structures, accompanied by the partial mistargeting of glutelins to the extracellular space. The gpa7 mutant was altered in the CCZ1 locus, which encodes the rice homolog of Arabidopsis (Arabidopsis thaliana) CALCIUM CAFFEINE ZINC SENSITIVITY1a (CCZ1a) and CCZ1b. Biochemical evidence showed that rice CCZ1 interacts with MONENSIN SENSITIVITY1 (MON1) and that these proteins function together as the Rat brain 5 (Rab5) effector and the Rab7 guanine nucleotide exchange factor (GEF). Notably, loss of CCZ1 function promoted the endosomal localization of vacuolar protein sorting-associated protein 9 (VPS9), which is the GEF for Rab5 in plants. Together, our results indicate that the MON1–CCZ1 complex is involved in post-Golgi trafficking of rice storage protein through a Rab5- and Rab7-dependent pathway.
- Subjects :
- Crops, Agricultural
0106 biological sciences
China
Genotype
Glutens
Physiology
Mutant
Vesicular Transport Proteins
Plant Science
Genes, Plant
01 natural sciences
03 medical and health sciences
symbols.namesake
Gene Expression Regulation, Plant
Glutelin
Arabidopsis
Genetics
Storage protein
Arabidopsis thaliana
030304 developmental biology
chemistry.chemical_classification
0303 health sciences
biology
Effector
Genetic Variation
food and beverages
Oryza
Golgi apparatus
biology.organism_classification
Focus Issue on Transport and Signaling
Cell biology
chemistry
rab GTP-Binding Proteins
Mutation
Seeds
symbols
biology.protein
Guanine nucleotide exchange factor
010606 plant biology & botany
Subjects
Details
- ISSN :
- 15322548 and 00320889
- Volume :
- 187
- Database :
- OpenAIRE
- Journal :
- Plant Physiology
- Accession number :
- edsair.doi.dedup.....ebfc7261aba061251a7afb230f3af780