1. Divalent cations and redox conditions regulate the molecular structure and function of visinin-like protein-1.
- Author
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Wang, Conan K, Simon, Anne, Jessen, Christian M, Oliveira, Cristiano LP, Mack, Lynsey, Braunewell, Karl-Heinz, Ames, James B, Pedersen, Jan Skov, and Hofmann, Andreas
- Subjects
Cell Line ,Cations ,Divalent ,Chromatography ,Gel ,Spectrometry ,Mass ,Matrix-Assisted Laser Desorption-Ionization ,Amino Acid Sequence ,Protein Conformation ,Sequence Homology ,Amino Acid ,Oxidation-Reduction ,Scattering ,Radiation ,Models ,Molecular ,Molecular Sequence Data ,Neurocalcin ,Cations ,Divalent ,Chromatography ,Gel ,Models ,Molecular ,Scattering ,Radiation ,Sequence Homology ,Amino Acid ,Spectrometry ,Mass ,Matrix-Assisted Laser Desorption-Ionization ,General Science & Technology - Abstract
The NCS protein Visinin-like Protein 1 (VILIP-1) transduces calcium signals in the brain and serves as an effector of the non-retinal receptor guanylyl cyclases (GCs) GC-A and GC-B, and nicotinic acetyl choline receptors (nAchR). Analysis of the quaternary structure of VILIP-1 in solution reveals the existence of monomeric and dimeric species, the relative contents of which are affected but not exclusively regulated by divalent metal ions and Redox conditions. Using small-angle X-ray scattering, we have investigated the low resolution structure of the calcium-bound VILIP-1 dimer under reducing conditions. Scattering profiles for samples with high monomeric and dimeric contents have been obtained. The dimerization interface involves residues from EF-hand regions EF3 and EF4.Using monolayer adsorption experiments, we show that myristoylated and unmyristoylated VILIP-1 can bind lipid membranes. The presence of calcium only marginally improves binding of the protein to the monolayer, suggesting that charged residues at the protein surface may play a role in the binding process.In the presence of calcium, VILIP-1 undergoes a conformational re-arrangement, exposing previously hidden surfaces for interaction with protein partners. We hypothesise a working model where dimeric VILIP-1 interacts with the membrane where it binds membrane-bound receptors in a calcium-dependent manner.
- Published
- 2011