Arabidopsis Cor15am Is a Chloroplast Stromal Protein That Has Cryoprotective Activity and Forms Oligomers

Nakayama, Katsuhiro; Okawa, Kumiko; Kakizaki, Tomohiro; Honma, Takenori; Itoh, Hideaki; Inaba, Tomoki

doi:10.1104/pp.106.094581

Cited by 124 publications

(109 citation statements)

References 44 publications

Supporting

Mentioning

102

Contrasting

Order By: Relevance

“…1B) Several LEA proteins from both plants and invertebrates are able to stabilize sensitive enzymes such as LDH during freezing or drying in vitro (Battaglia et al, 2008;Tunnacliffe et al, 2010). Because such an activity was previously reported for COR15A as well (Lin and Thomashow, 1992a;Nakayama et al, 2007Nakayama et al, , 2008, we tested it for the recombinant COR15A and COR15B proteins previously described (Thalhammer et al, 2010). The assay involved freezing of enzyme samples in liquid nitrogen and thawing at room temperature.…”

Section: Cor15a and Cor15b Are Necessary For Arabidopsis To Attain Fumentioning

confidence: 99%

“…Although it was shown that constitutive expression of COR15A leads to increased freezing tolerance in nonacclimated Arabidopsis plants (Artus et al, 1996), the contribution of the COR15 proteins to the increased freezing tolerance during cold acclimation has not been investigated. Likewise, there is evidence that COR15 proteins function as both membrane (Artus et al, 1996;Uemura et al, 1996;Steponkus et al, 1998) and enzyme stabilizers (Lin and Thomashow, 1992;Nakayama et al, 2007Nakayama et al, , 2008. However, it is unclear whether any chloroplast enzymes are inactivated during freezing in vivo, or whether cold acclimation has any effect on enzyme stability in vivo.…”

mentioning

confidence: 99%

“…The recombinant protein prevents phospholipid vesicle fusion, but not leakage of soluble content , and protects the activity of the enzyme lactate dehydrogenase (LDH) during freezing in liquid nitrogen (Lin and Thomashow, 1992a;Nakayama et al, 2007Nakayama et al, , 2008. In addition, COR15A prevents aggregation of the isolated chloroplast enzyme Rubisco during drying (Nakayama et al, 2007). The closest homolog of COR15A is COR15B, with 82% nucleic acid sequence identity (Wilhelm and Thomashow, 1993).…”

mentioning

confidence: 99%

“…Constitutive expression of COR15A increases the freezing tolerance of Arabidopsis chloroplasts in leaves and of isolated protoplasts by 1°C to 2°C (Artus et al, 1996). The recombinant protein prevents phospholipid vesicle fusion, but not leakage of soluble content , and protects the activity of the enzyme lactate dehydrogenase (LDH) during freezing in liquid nitrogen (Lin and Thomashow, 1992a;Nakayama et al, 2007Nakayama et al, , 2008. In addition, COR15A prevents aggregation of the isolated chloroplast enzyme Rubisco during drying (Nakayama et al, 2007).…”

mentioning

confidence: 99%

“…The genes are localized in the nuclear genome, where they are arranged as a tandem repeat. The encoded proteins are targeted to the chloroplast stroma via signal peptides (Lin and Thomashow, 1992b;Nakayama et al, 2007;Candat et al, 2013) resulting in mature proteins of about 9 kD. Both mature proteins are highly hydrophilic and predominantly unstructured in solution, whereas they fold into amphipathic a-helices during drying.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Disordered Cold Regulated15 Proteins Protect Chloroplast Membranes during Freezing through Binding and Folding, But Do Not Stabilize Chloroplast Enzymes in Vivo

et al. 2014

View full text Add to dashboard Cite

Freezing can severely damage plants, limiting geographical distribution of natural populations and leading to major agronomical losses. Plants native to cold climates acquire increased freezing tolerance during exposure to low nonfreezing temperatures in a process termed cold acclimation. This involves many adaptative responses, including global changes in metabolite content and gene expression, and the accumulation of cold-regulated (COR) proteins, whose functions are largely unknown. Here we report that the chloroplast proteins COR15A and COR15B are necessary for full cold acclimation in Arabidopsis (Arabidopsis thaliana). They protect cell membranes, as indicated by electrolyte leakage and chlorophyll fluorescence measurements. Recombinant COR15 proteins stabilize lactate dehydrogenase during freezing in vitro. However, a transgenic approach shows that they have no influence on the stability of selected plastidic enzymes in vivo, although cold acclimation results in increased enzyme stability. This indicates that enzymes are stabilized by other mechanisms. Recombinant COR15 proteins are disordered in water, but fold into amphipathic a-helices at high osmolyte concentrations in the presence of membranes, a condition mimicking molecular crowding induced by dehydration during freezing. X-ray scattering experiments indicate protein-membrane interactions specifically under such crowding conditions. The COR15-membrane interactions lead to liposome stabilization during freezing. Collectively, our data demonstrate the requirement for COR15 accumulation for full cold acclimation of Arabidopsis. The function of these intrinsically disordered proteins is the stabilization of chloroplast membranes during freezing through a folding and binding mechanism, but not the stabilization of chloroplastic enzymes. This indicates a high functional specificity of these disordered plant proteins.

show abstract