Chromatin immunoprecipitation (ChIP) is one of the most powerful methods to identify and characterize the association of proteins with specific genomic regions in the context of intact cells. In this method, cells are first treated with formaldehyde to crosslink protein-protein and p ...
Ras-related small GTPases serve as critical regulators for a wide range of cellular signaling pathways and are activated by the conversion of the GDP-bound state to the GTP-bound conformation. Until recently, measurement of the GTP-bound active form of Ras-related G proteins involved im ...
β-O-linked N-acetylglucosamine (O-GlcNAc) is posttranslationally added to serine and threonine residues of many nuclear and cytoplasmic proteins found in metazoans. This modification is dynamic and responsive to numerous stimuli and conditions, suggesting an important ro ...
Lipid phosphate molecules such as phosphatidate, lysophosphatidate, and diacylglycerol pyrophosphate play roles as signaling molecules in prokaryotic and eukaryotic cells. The cellular processes by which lipid phosphate molecules signal may be attenuated through the ac ...
Proteins can be methylated on the side-chain nitrogens of arginine and lysine residues or on carboxy-termini. Protein methylation is a way of subtly changing the primary sequence of a peptide so that it can encode more information. This common posttranslational modification is implicat ...
The roles of phosphoinositide second messengers as signaling molecules in a vast array of cellular processes including cell growth, metabolism, vesicular transport, programmed cell death, and responses to extracellular signals are only beginning to be understood. The recent ide ...
Phosphoinositides are a vitally important class of intracellular-signaling molecules that regulate cellular processes, including signaling through cell-surface receptors, remodeling of the cytoskeleton, vesicle-mediated protein trafficking, and various nucl ...
Mammalian cells contain many structurally and functionally diverse phospholipases A2 (PLA2) that catalyze the hydrolysis of sn-2 fatty acid from membrane phospholipid. Assays are described for measuring the activity of Group IVA cytosolic PLA2α (cPLAα) and for secreted PLA2s (sPL ...
The emerging technique of bioluminescence resonance energy transfer (BRET) allows us to detect protein interactions in live cells and in real time, thus providing a new window into cellular signal transduction processes. We present experimental protocols for expressing fusion pr ...
Green fluorescent proteins (GFPs) are widely used tools to visualize proteins and study their intracellular distribution. One feature of working with GFP variants, photobleaching, has recently been combined with an older technique known as fluorescence recovery after photoble ...
A wide variety of methods used in the study of signal transduction in eukaryotes rely on the ability to precipitate proteins from whole cell extracts. Immunoprecipitation and related methods of affinity purification are routinely used to assess binding partner interactions and enzy ...
Signal transduction pathways mediate cell-cell interactions and integrate signals from the extracellular environment through specific receptors at the cell membrane. They play a pivotal role in regulating cellular growth and differentiation and in mediating many physiolo ...
Translocation of proteins from the mitochondrial intermembrane space to the cytoplasm is a critical event during apoptosis. There are several methods for assaying this event cited in the literature. In this chapter, we highlight separation of cytosolic and mitochondrial fractions ...
In eukaryotic organisms gene expression is regulated through a variety of upstream transacting factors (transcription factors) whose primary function appears to be the targeting of coregulatory protein complexes, which interact with basal transcription machinery to define ...
Two-dimensional electrophoresis (2-DE) is a powerful technique to differentially display patterns of protein expression and posttranslational modifications, providing a good strategy to monitor molecular responses induced by the activation or inactivation of specific ...
Controlling the stability of cellular proteins is a fundamental way by which cells regulate growth, differentiation, survival, and development. Measuring the turnover rate of a protein is often the first step in assessing whether or not the function of a protein is regulated by proteolysis u ...
Protein kinases, encoded by approx 2% of eukaryotic genes, represent one of the major classes of cell-regulatory molecules. Assessment of the catalytic activity of a specific protein kinase can be an important step in elucidating signal-transduction pathways that affect cell behavio ...
Methods are presented for purifying bovine testes calmodulin and the calmodulin-regulated plasma-membrane calcium ATPase from human erythrocytes by calcium dependent affinity chromatography. The assay of CaM Kinase II using a synthetic peptide substrate is also described.
Understanding how phosphorylation regulates the behavior of individual proteins is critical to understanding signaling pathways. These studies usually involve knowledge of which amino acid residues are phosphorylated on a given protein and the extent of such a modification. Th ...
Elucidating mechanisms controlling nuclear processes requires an understanding of the nucleoprotein structure of genes at endogenous chromosomal loci. Traditional approaches to measuring protein-DNA interactions in vitro have often failed to provide insights into phy ...