Calmodulin:
A heat-stable, low-molecular-weight activator protein found mainly in the brain and heart. The binding of calcium ions to this protein allows this protein to bind to cyclic nucleotide phosphodiesterases and to adenyl cyclase with subsequent activation. Thereby this protein modulates cyclic Amp and cyclic Gmp levels.
JoVE General
Pull-down of Calmodulin-binding Proteins
Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin
Calmodulin (CaM) pull-down assay is an effective way to investigate the interaction of CaM with various proteins. This method uses CaM-sepharose beads for efficient and specific analysis of CaM-binding proteins. This provides an important tool to explore CaM signaling in cellular function.
JoVE General
Identification of Protein Complexes in Escherichia coli using Sequential Peptide Affinity Purification in Combination with Tandem Mass Spectrometry
1Banting and Best Department of Medical Research, Donnelly Centre, University of Toronto, 2Deparment of Biochemistry, Research and Innovation Centre, University of Regina, 3Department of Medical Genetics and Microbiology, University of Toronto
Affinity purification of tagged proteins in combination with mass spectrometry (APMS) is a powerful method for the systematic mapping of protein interaction networks and for investigating the mechanistic basis of biological processes. Here, we describe an optimized sequential peptide affinity (SPA) APMS procedure developed for the bacterium Escherichia coli that can be used to isolate and characterize stable multi-protein complexes to near homogeneity even starting from low copy numbers per cell.
JoVE General
Dissection of Hippocampal Dentate Gyrus from Adult Mouse
1Japan Science and Technology Agency, Core Research for Evolutionary Science and Technology (CREST), 2Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 3Department of Psychiatry, Graduate School of Medicine, Kyoto University, 4Genetic Engineering and Functional Genomics Group, Horizontal Medical Research Organization, Graduate School of Medicine, Kyoto University, 5Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences
A dissection technique for removal of the dentate gyrus from adult mouse under a stereomicroscope was demonstrated in this video-recorded protocol.
JoVE General
Ambulatory ECG Recording in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Telemetric ECG has emerged as an essential tool in evaluating animal models for cardiac arrhythmias and sudden cardiac death. Here, we present a stepwise guide to telemetric ECG recordings for application in long-term ambulatory ECG monitoring in mice.
JoVE Neuroscience
In vivo Neuronal Calcium Imaging in C. elegans
1Department of Physiology and Biophysics, Boston University School of Medicine, 2Boston University Photonics Center
With its small transparent body, well-documented neuroanatomy and a host of amenable genetic techniques and reagents, C. elegans makes an ideal model organism for in vivo neuronal imaging using relatively simple, low-cost techniques. Here we describe single neuron imaging within intact adult animals using genetically encoded fluorescent calcium indicators.
JoVE General
Live Cell Calcium Imaging Combined with siRNA Mediated Gene Silencing Identifies Ca2+ Leak Channels in the ER Membrane and their Regulatory Mechanisms
1Medical Biochemistry and Molecular Biology, Saarland University, 2Experimental and Clinical Pharmacology and Toxicology, Saarland University
The endoplasmic reticulum plays a key role in protein biogenesis and in calcium homeostasis. We have established an experimental system that allows us to address the role of Ca2+ leak channels and to characterize their putative regulatory mechanisms. This system involves siRNA mediated gene silencing and live cell Ca2+ imaging.
JoVE General
A β-glucuronidase (GUS) Based Cell Death Assay
Programmed cell death assays commonly used in mammalian systems such as DNA laddering or TUNEL assays, are often difficult to reproduce in plants. In combination with a GUS reporter system, we propose a rapid, plant based transient assay to analyze the potential death properties of specific genes.
JoVE General
Monitoring Dynamic Changes In Mitochondrial Calcium Levels During Apoptosis Using A Genetically Encoded Calcium Sensor
Department of Neuroscience and Cell Biology, University of Texas Medical Branch
This protocol describes a method for real-time measurement of mitochondrial calcium fluxes by fluorescent imaging. The method takes advantage of a circularly permutated YFP-based dual-excitation ratiometric calcium sensor (ratiometric pericam-mt) selectively expressed in mitochondria.
JoVE General
Proteomics to Identify Proteins Interacting with P2X2 Ligand-Gated Cation Channels
1Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, 2Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, 3Department of Anesthesiology, Medicine and Physiology, David Geffen School of Medicine, University of California, Los Angeles
We describe a simple protocol to identify brain proteins that bind to the full length C terminus of ATP-gated P2X2 receptors. The extension and systematic application of this approach to all P2X receptors is expected to lead to a better understanding of P2X receptor signaling.
JoVE Clinical and Translational Medicine
Programmed Electrical Stimulation in Mice
1Department of Molecular Physiology and Biophysics, Baylor College of Medicine (BCM), 2The Margaret M. and Albert B. Alkek Department of Medicine, Baylor College of Medicine (BCM)
Programmed electrical stimulation provides the ability to determine conduction properties of the heart, and the possibility to induce and terminate cardiac arrhythmias using various pacing protocols. Using a transvenous catheter, intracardiac electrogram recordings can be obtained in mice following programmed electrical stimulation protocols to identify arrhythmogenic substrates.
JoVE Neuroscience
Post-embedding Immunogold Labeling of Synaptic Proteins in Hippocampal Slice Cultures
1Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 2Department of Microbiology and Molecular Genetics, Medical College of Wisconsin
The localization and distribution of proteins provide important information for understanding their cellular functions. The superior spatial resolution of electron microscopy (EM) can be used to determine the subcellular localization of a given antigen following immunohistochemistry. For tissues of the central nervous system (CNS), preserving structural integrity while maintaining antigenicity has been especially difficult in EM studies. Here, we adopt a procedure that has been used to preserve structures and antigens in the CNS to study and characterize synaptic proteins in rat hippocampal CA1 pyramidal neurons.
JoVE Editorial
The 2009 Lindau Nobel Laureate Meeting: Roger Y. Tsien, Chemistry 2008
American biochemist Roger Tsien shared the 2008 Nobel Prize in Chemistry with Martin Chalfie and Osamu Shimomura for their discovery and development of the Green Fluorescent Protein (GFP). Tsien dramatically improved the wild-type GFP resulting in increased fluorescence, increased photostability, and a shift in the major excitation peak to 488 nm (matching FITC).
JoVE General
Modeling Biological Membranes with Circuit Boards and Measuring Electrical Signals in Axons: Student Laboratory Exercises
1Department of Biology, University of Kentucky, 2Department of Physiology, University of Toronto
This is a demonstration of how biological membranes can be understood using electrical models. We also demonstrate procedures for recording action potentials from the ventral nerve cord of the crayfish for student orientated laboratories.
JoVE Neuroscience
Analyzing Responses of Mouse Olfactory Sensory Neurons Using the Air-phase Electroolfactogram Recording
Biology, Johns Hopkins University
The electroolfactogram (EOG) recording is an informative, easy-to-conduct, and reliable way of assessing olfactory function at the level of the olfactory epithelium. This protocol describes a recording setup, mouse tissue preparation, data collection, and basic data analysis.
JoVE Neuroscience
Dissection of Adult Mouse Utricle and Adenovirus-mediated Supporting-cell Infection
1Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 2Department of Microbiology & Immunology, Medical University of South Carolina, 3National Institute on Deafness and Other Communication Disorders, National Institutes of Health
Mechanosensory hair cells are the receptor cells of the inner ear. The best-characterized in vitro model system of mature mammalian hair cells utilizes organ cultures of utricles from adult mice. We present the dissection of the adult mouse utricle, and we demonstrate adenovirus-mediated infection of supporting cells in cultured utricles.
JoVE General
Direct Imaging of ER Calcium with Targeted-Esterase Induced Dye Loading (TED)
1Institute for Clinical Neurobiology, University of Wuerzburg, 2Department of Synapses - Circuits - Plasticity, Max Planck Institute of Neurobiology, Martinsried, 3Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University of Munich
Targeted-esterase induced dye loading (TED) supports the analysis of intracellular calcium store dynamics by fluorescence imaging. The method bases on targeting of a recombinant Carboxylesterase to the endoplasmic reticulum (ER), where it improves the local unmasking of synthetic low-affinity Ca2+ indicator dyes in the ER lumen.
JoVE Clinical and Translational Medicine
Intraductal Injection of LPS as a Mouse Model of Mastitis: Signaling Visualized via an NF-κB Reporter Transgenic
1Cancer Biology Department, Vanderbilt University Medical Center, 2Department of Medicine, Vanderbilt University Medical Center, 3Department of Pharmaceutical Sciences, University of Hawaii at Hilo College of Pharmacy
Described here is a technique in which lipopolysaccharide is injected into the lactating mouse mammary gland via the nipple to simulate mastitis, a condition commonly caused by bacterial infection. Lipopolysaccharide injection results in increased nuclear factor kappa B (NF-κB) signaling, visualized through bioluminescent imaging of an NF-κB luciferase reporter mouse.
JoVE Neuroscience
T-maze Forced Alternation and Left-right Discrimination Tasks for Assessing Working and Reference Memory in Mice
1Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 2Japan Science and Technology Agency, Core Research for Evolutionary Science and Technology (CREST), 3Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences
This article presents the protocol of T-maze tests using a modified automated apparatus for assessing the learning and memory functions in mice.
JoVE Immunology and Infection
Measurement of Cytosolic Ca2+ in Isolated Contractile Lymphatics
Department of Physiology, School of Medicine, Louisiana State University Health Sciences Center
We introduce an approach to evaluate the cytosolic Ca2+ concentration in isolated lymphatics to study Ca2+-dependent and Ca2+-sensitizing mechanisms of lymphatic smooth muscle contraction.
JoVE General
Organotypic Culture of Adult Rabbit Retina
Havard Medical School, MGH - Massachusetts General Hospital
This article demonstrates the dissection and incubation of rabbit retina and particle-mediated gene transfer of plasmids encoding GFP or a variety of subcellular markers into retinal ganglion cells.
JoVE General
Real-time Analyses of Retinol Transport by the Membrane Receptor of Plasma Retinol Binding Protein
Here we describe an optimized technique to produce high-quality vitamin A/RBP complex and two real-time monitoring techniques to study vitamin A transport by STRA6, the RBP receptor.
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