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Lignin Down-regulation of Zea mays via dsRNAi and Klason Lignin Analysis
Published on: July 23, 2014
Calmodulin binds to maize lipid transfer protein and modulates its lipids binding ability
Cuifeng Li1, Wanqin Xie, Wenyan Bai
1Department of Biochemistry and Molecular Biology, Nankai University, Tianjin, China. licf@nankai.edu.cn
The FEBS Journal
|September 23, 2008
Summary
Maize non-specific lipid transfer protein (Zm-LTP) binds calmodulin (CaM) independently of calcium. This interaction, crucial for Zm-LTP regulation, involves specific amino acids and may be common across plant lipid transfer proteins.
Area of Science:
- Plant molecular biology
- Protein-protein interactions
- Biochemistry
Background:
- Plant non-specific lipid transfer proteins (ns-LTPs) bind hydrophobic molecules in vitro, but their in vivo functions, especially in defense responses like systemic acquired resistance, are not well understood.
- Regulation of ns-LTPs, particularly their interaction with signaling molecules, is a key area for understanding their physiological roles.
Purpose of the Study:
- To investigate the interaction between maize non-specific lipid transfer protein (Zm-LTP) and calmodulin (CaM).
- To identify the CaM-binding site on Zm-LTP and determine the key amino acid residues involved.
- To explore the effect of CaM on Zm-LTP's lipid-binding activity and compare CaM-binding motifs across different plant LTPs.
Main Methods:
- Mapping the CaM-binding site on Zm-LTP using amino acid region analysis.
- Site-directed mutagenesis to identify crucial amino acid residues for CaM binding (R46, R47, K54, R58).
- Assessing Zm-LTP lipid-binding activity in the presence of CaM and various Ca2+ modulators (EGTA, W7, TFP).
- Comparative analysis of CaM-binding motifs in LTPs from different plant species.
Main Results:
- Zm-LTP binds to CaM in a calcium-independent manner.
- The CaM-binding site on Zm-LTP was localized to amino acids 46-60, with residues R46, R47, K54, and R58 being critical for binding.
- CaM's effect on Zm-LTP lipid-binding activity was investigated under different conditions.
- Significant structural differences were observed in CaM-binding motifs among LTPs from various species.
Conclusions:
- The interaction between Zm-LTP and CaM is calcium-independent and mediated by specific amino acid residues.
- CaM binding represents a potential regulatory mechanism for ns-LTPs' physiological functions.
- The findings suggest that CaM interaction might be a conserved feature among plant LTPs, offering insights into their diverse roles.
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