Crystallization and preliminary X-ray crystallographic analysis of macrophage/microglia-specific calcium-binding
Mitsugu Yamada1, Yoshinori Imai, Shinichi Kohsaka
1Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
Abstract:
Iba1 (ionized calcium-binding adaptor molecule 1) is expressed specifically in macrophages/microglia and is involved in the activation of Rac, coordinating the reorganization of the actin cytoskeleton followed by the formation of lamellipodia and membrane ruffles, which are typical properties of activated microglia. Human Iba1 and mouse Iba1 were overexpressed and crystallized. The crystals belong to a monoclinic system, with space group C2 and unit-cell parameters a = 60.75, b = 36.61, c = 99.71 A, beta = 99.71 degrees for human Iba1 and a = 76.28, b = 44.06, c = 99.13 A, beta = 90.03 degrees for mouse Iba1. Both crystals diffracted well to a resolution of 2.1 A and initial phase determinations were attempted by a molecular-replacement method using calmodulin structures.
Insights
Ionized calcium-binding adaptor molecule 1 (Iba1) is crucial for microglial activation. Researchers successfully crystallized human and mouse Iba1, enabling further structural studies of this key protein.
Area of Science:
- Neuroscience
- Structural Biology
- Immunology
Background:
- Ionized calcium-binding adaptor molecule 1 (Iba1) is a specific marker for macrophages and microglia.
- Iba1 plays a role in Rac activation, actin cytoskeleton reorganization, and the formation of lamellipodia and membrane ruffles, characteristic of activated microglia.
Purpose of the Study:
- To obtain high-quality crystals of human and mouse Iba1 for structural determination.
- To facilitate detailed structural analysis of Iba1 to understand its function in microglial activation.
Main Methods:
- Overexpression and crystallization of human and mouse Iba1.
- X-ray diffraction analysis of the obtained crystals.
- Molecular replacement method using calmodulin structures for initial phase determination.
Main Results:
- Crystals of human and mouse Iba1 were obtained, belonging to the monoclinic system (space group C2).
- Unit-cell parameters for human Iba1: a = 60.75, b = 36.61, c = 99.71 Å, β = 99.71°. Unit-cell parameters for mouse Iba1: a = 76.28, b = 44.06, c = 99.13 Å, β = 90.03°.
- Crystals diffracted to a resolution of 2.1 Å, suitable for structural analysis.
Conclusions:
- The successful crystallization and diffraction of Iba1 provide a foundation for determining its 3D structure.
- Understanding Iba1's structure will elucidate its mechanism in regulating microglial function and activation states.
More Related Videos
10:52Correlative Light and Electron Microscopy to Study Microglial Interactions with β-Amyloid Plaques
Published on: June 1, 2016
11:10Antibody Binding Specificity for Kappa (Vκ) Light Chain-containing Human (IgM) Antibodies: Polysialic Acid (PSA) Attached to NCAM as a Case Study
Published on: June 29, 2016