Katz, Adriana , Waridel, Patrice , Shevchenko, Andrej , Pick, Uri .
Salt-induced changes in the plasma membrane proteome of the halotolerant alga Dunaliella salina.
The halotolerant alga Dunaliella salina is a recognized model photosynthetic organism for studying plant adaptation to high salinity. The adaptation mechanisms involve major changes in the proteome composition associated with energy metabolism and carbon and iron acquisition. In order to clarify the molecular basis for the remarkable resistance to high salinity, we performed a comprehensive proteomic analysis of the plasma membrane, with the aim to identify changes in the membrane protein composition and organization at high salinity. Plasma membrane proteins were recognized by tagging intact cells with a membrane-impermeable biotin derivative. Proteins were resolved by two-dimensional Blue Native/SDS-PAGE and identified by nanoLC-MS/MS. Out of 55 identified proteins, about 60% were integral membrane or membrane-associated. We identified novel surface coat proteins, lipid metabolizing enzymes, a new family of membrane proteins of unknown function, ion transporters, small GTP-binding proteins and heat shock proteins. The abundance of 20 protein spots increased and of 2 protein spots decreased under high salt. The major salt-regulated proteins included elements that function in protein and membrane structure stabilization and factors within signal transduction pathways. The migration profiles of native protein complexes on BN gels revealed oligomerization or comigration of major surface-exposed proteins, which may indicate mechanisms of stabilization at high salinity.
This comprehensive overview of a plasma membrane proteome in an extreme halotolerant organism may shed light on novel mechanisms of adaptation to high salt.
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1 - Weizmann Institute of Science, Biological chemistry, Rehovot, 76100, Israel
2 - University of Lausanne
3 - Max Planck Institute of Molecular Cell Biology and Genetics
4 - Weizmann Institute of Science
Presentation Type: ASPB Minisymposium
Location: Continental A/Hilton
Date: Sunday, July 8th, 2007
Time: 5:00 PM