title: Ribosomal P3 protein AtP3B of Arabidopsis acts as both protein and RNA chaperone to increase tolerance of heat and cold stresses.
abstract: The P3 proteins are plant-specific ribosomal P-proteins; however, their molecular functions have not been characterized. In a screen for components of heat-stable high-molecular weight (HMW) complexes, we isolated the P3 protein AtP3B from heat-treated Arabidopsis suspension cultures. By size-exclusion chromatography (SEC), SDS-PAGE and native PAGE followed by immunoblotting with anti-AtP3B antibody, we showed that AtP3B was stably retained in HMW complexes following heat shock. The level of AtP3B mRNA increased in response to both high- and low-temperature stresses. Bacterially expressed recombinant AtP3B protein exhibited both protein and RNA chaperone activities. Knockdown of AtP3B by RNAi made plants sensitive to both high- and low-temperature stresses, whereas overexpression of AtP3B increased tolerance of both conditions. Together, our results suggest that AtP3B protects cells against both high- and low-temperature stresses. These findings provide novel insight into the molecular functions and in vivo roles of acidic ribosomal P-proteins, thereby expanding our knowledge of the protein production machinery.
authors.affiliation: Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea.
authors.forename: Chang Ho
authors.initials: CH
authors.lastname: Kang
authors.affiliation: Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea.|Genetics and Breeding Research Center, NFRDI, Geoje, 656-842, Korea.
authors.forename: Young Mee
authors.initials: YM
authors.lastname: Lee
authors.affiliation: Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea.
authors.forename: Joung Hun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea.
authors.forename: Ganesh M
authors.initials: GM
authors.lastname: Nawkar
authors.affiliation: Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea.
authors.forename: Hun Taek
authors.initials: HT
authors.lastname: Oh
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Science, Gyeongsang National University, Jinju, 660-701, Korea.
authors.forename: Min Gab
authors.initials: MG
authors.lastname: Kim
authors.affiliation: Department of Agricultural Biotechnology, National Academy of Agricultural Science (NAAS), Jeonju, 560-500, Korea.
authors.forename: Soo In
authors.initials: SI
authors.lastname: Lee
authors.affiliation: Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea.
authors.forename: Woe Yeon
authors.initials: WY
authors.lastname: Kim
authors.affiliation: Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea.
authors.forename: Dae-Jin
authors.initials: DJ
authors.lastname: Yun
authors.affiliation: Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea.
authors.forename: Sang Yeol
authors.initials: SY
authors.lastname: Lee
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D003080:Cold Temperature; D015180:Electrophoresis, Gel, Two-Dimensional; D018832:Molecular Chaperones / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013312:Stress, Physiological; D000071436:Thermotolerance
chemical_list: D029681:Arabidopsis Proteins; D018832:Molecular Chaperones; D012269:Ribosomal Proteins; C000625485:ribosomal P3 protein, Arabidopsis
keywords: acidic ribosomal P-proteins; cellular protection; growth; protein chaperone