2007 Fiscal Year Final Research Report Summary
Influence of freezing tolerance related proteins in the cryobehavior of the plasma membrane
| Project/Area Number |
17380062
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Applied biochemistry
|
|---|
| Research Institution | Iwate University |
|---|
Principal Investigator |
UEMURA Matsuo Iwate University, Faculty of Agriculture, Professor (00213398)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ITO Kikukatsu Faculty of Agriculture, 農学部, Professor (50232434)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Keywords | Environmental Adaptation / Plasma Membrane / Proteins / Cold-induced Genes / Freezing Injury / Cold Acclimation / Freezing Tolerance / Microdomains |
|---|
| Research Abstract |
The objective of this project was to elucidate function of cold-responsive plasma membrane proteins in cold acclimation of plants using Arabidopsis thaliana. We specifically determined whether these cold-responsive proteins increase the cryostability of the plasma membrane during a freeze/thaw cycle. Arabidopsis lipocalin-like protein (AtLCN), which quickly and significantly accumulated in the plasma membrane during cold acclimation, affects plant freezing tolerance: overexpression of AtLCN resulted in an increase in freezing tolerance and the incidence of expansion-induced lysis seemed to mitigate in the transgenic lines. We found that AtLCN bound to plasma membrane phospholipids, especially acidic phospholipids, and minimized the incidence of freeze-induced fusion of liposomes containing acidic phospholipids. Thus, we now hypothesize that AtLCN electrostatically interacts with phospholipids and, hence, stabilize the plasma membrane against freezes-induced destabilization.
The plasma membrane is known to have a number of microdomains with distinct lipid and protein components, called as membrane microdomains or membrane rafts. We performed proteome analysis of microdomain-localized proteins in the plasma membrane and compared the composition before and after cold acclimation. We found that a number of proteins with deduced function of cell wall-plasma membrane interaction, membrane trafficking and cytosketon-associated functions altered dynamically during cold acclimation. Among functions associated with plasma membrane microdomains, membrane repair system seems to be important in maintaining cell survival under mechanical stress conditions such as during a freeze/thaw cycle. We now focus on plasma membrane proteins, synaptotagmins, one of which accumulated in the plasma membrane quickly during cold acclimation, to elucidate whether membrane repair system is involved in plant freezing tolerance.
|
