RRC ID 30776
Author Karim S, Alezzawi M, Garcia-Petit C, Solymosi K, Khan NZ, Lindquist E, Dahl P, Hohmann S, Aronsson H.
Title A novel chloroplast localized Rab GTPase protein CPRabA5e is involved in stress, development, thylakoid biogenesis and vesicle transport in Arabidopsis.
Journal Plant Mol. Biol.
Abstract A novel Rab GTPase protein in Arabidopsis thaliana, CPRabA5e (CP = chloroplast localized) is located in chloroplasts and has a role in transport. Transient expression of CPRabA5e:EGFP fusion protein in tobacco (Nicotiana tabacum) leaves, and immunoblotting using Arabidopsis showed localization of CPRabA5e in chloroplasts (stroma and thylakoids). Ypt31/32 in the yeast Saccharomyces cerevisiae are involved in regulating vesicle transport, and CPRabA5e a close homolog of Ypt31/32, restores the growth of the ypt31Δ ypt32(ts) mutant at 37 °C in yeast complementation. Knockout mutants of CPRabA5e displayed delayed seed germination and growth arrest during oxidative stress. Ultrastructural studies revealed that after preincubation at 4 °C mutant chloroplasts contained larger plastoglobules, lower grana, and more vesicles close to the envelopes compared to wild type, and vesicle formation being enhanced under oxidative stress. This indicated altered thylakoid development and organization of the mutants. A yeast-two-hybrid screen with CPRabA5e as bait revealed 13 interacting partner proteins, mainly located in thylakoids and plastoglobules. These proteins are known or predicted to be involved in development, stress responses, and photosynthesis related processes, consistent with the stress phenotypes observed. The results observed suggest a role of CPRabA5e in transport to and from thylakoids, similar to cytosolic Rab proteins involved in vesicle transport.
Volume 84(6)
Pages 675-92
Published 2014-4
DOI 10.1007/s11103-013-0161-x
PMID 24337800
MeSH Amino Acid Sequence Arabidopsis / enzymology* Arabidopsis / genetics Arabidopsis / physiology Arabidopsis / ultrastructure Arabidopsis Proteins / genetics* Arabidopsis Proteins / metabolism Biological Transport Chloroplasts / enzymology* Chloroplasts / ultrastructure Cold Temperature Molecular Sequence Data Oxidative Stress Phenotype Phylogeny Plant Leaves / enzymology Plant Leaves / genetics Plant Leaves / physiology Plant Leaves / ultrastructure Protein Structure, Tertiary Recombinant Fusion Proteins Saccharomyces cerevisiae / genetics Saccharomyces cerevisiae / metabolism Seedlings / enzymology Seedlings / genetics Seedlings / physiology Seedlings / ultrastructure Seeds / enzymology Seeds / genetics Seeds / physiology Seeds / ultrastructure Sequence Deletion Stress, Physiological Thylakoids / enzymology Thylakoids / ultrastructure Two-Hybrid System Techniques rab GTP-Binding Proteins / genetics* rab GTP-Binding Proteins / metabolism
IF 3.543
Times Cited 11
Arabidopsis / Cultured plant cells, genes pst00015 pst12661