abstract：:Determination of the three-dimensional structures of the globins led to the problem of determining how the ligands bound to the heme. In many of these structures there was no clear path from the solvent to the ligand-binding site. Even in those structures that appeared to have one or more tunnels from the exterior to ...

journal_title：Methods in enzymology

authors： Golden SD,Olsen KW

更新日期：2008-01-01 00:00:00

abstract：:The Escherichia coli fumarate and nitrate reductase (FNR) regulator protein is an important transcriptional regulator that controls the expression of a large regulon of more than 100 genes in response to changes in oxygen availability. FNR is active when it acquires a [4Fe-4S](2+) cluster under anaerobic conditions. T...

journal_title：Methods in enzymology

authors： Crack JC,Le Brun NE,Thomson AJ,Green J,Jervis AJ

更新日期：2008-01-01 00:00:00

abstract：:Crystallographic studies on flavodiiron proteins (FDPs) have revealed that the common sequence core ( approximately 400 residues) that defines this protein family comprises two structural domains. The N-terminal domain (of approximately 250 residues) displays a metallo-beta-lactamase-like-fold, being indeed structural...

journal_title：Methods in enzymology

authors： Vicente JB,Carrondo MA,Teixeira M,Frazão C

更新日期：2008-01-01 00:00:00

abstract：:Signal transduction by vascular endothelial growth factors (VEGFs) through their cognate VEGF receptor tyrosine kinases follows the consensus scheme for receptor tyrosine kinases. Thus, binding of ligand induces receptor dimerization and activation of the tyrosine kinase through transphosphorylation between receptor m...

journal_title：Methods in enzymology

authors： Li X,Claesson-Welsh L,Shibuya M

更新日期：2008-01-01 00:00:00

abstract：:Endothelial cell adhesion and migration is fundamental to a number of physiologic processes, including vascular development and angiogenesis. It has been investigated in a variety of contexts, including tumorigenesis, wound healing, tissue engineering, and biomaterial design. The chemical and mechanical extracellular ...

journal_title：Methods in enzymology

authors： Reinhart-King CA

更新日期：2008-01-01 00:00:00

abstract：:Oxidized phospholipids play an important role in execution of the mitochondrial stage of apoptosis and clearance of apoptotic cells by macrophages. Therefore, the identification and quantification of oxidized phospholipids generated during apoptosis are very important. These can be achieved successfully by a newly dev...

journal_title：Methods in enzymology

authors： Tyurin VA,Tyurina YY,Kochanek PM,Hamilton R,DeKosky ST,Greenberger JS,Bayir H,Kagan VE

更新日期：2008-01-01 00:00:00

abstract：:Lysosomes are specialized organelles for protein recycling and as such are involved in the terminal steps of autophagy. However, it has become evident that lysosomes also play an important role in the progression of apoptosis. This latter function seems to be dependent on lysosomal proteases, which need to be released...

journal_title：Methods in enzymology

authors： Ivanova S,Repnik U,Bojic L,Petelin A,Turk V,Turk B

更新日期：2008-01-01 00:00:00

abstract：:Nonsense-mediated mRNA decay (NMD) is activated by exon-junction complexes (EJCs) that are located downstream of the termination codon of the substrate mRNAs. This situation can be imitated by tethering components of the EJC to the 3' untranslated region (3' UTR) of a reporter mRNA. Here we describe the detailed use o...

journal_title：Methods in enzymology

authors： Gehring NH,Hentze MW,Kulozik AE

更新日期：2008-01-01 00:00:00

abstract：:Although most eukaryotic mRNAs are degraded by exonucleases acting on either end of the molecule, a subset of mRNAs undergo endonuclease cleavage within the mRNA body. Endonuclease cleavage can be activated by cellular stress, extracellular signals, or by ribosome stalling, as might occur at a premature termination co...

journal_title：Methods in enzymology

authors： Otsuka Y,Schoenberg DR

更新日期：2008-01-01 00:00:00

abstract：:Biochemical analysis of the components of the mRNA decay machinery is crucial to understand the mechanisms of mRNA decay. The Lsm1p-7p-Pat1p complex is a key activator of decapping in the 5' to 3'-mRNA decay pathway that is highly conserved in all eukaryotes. The first step in this pathway is poly(A) shortening that i...

journal_title：Methods in enzymology

authors： Tharun S

更新日期：2008-01-01 00:00:00

abstract：:Staphylococcus aureus ribonuclease III (Sa-RNase III) belongs to the enzyme family known to process double-stranded RNAs consisting of two turns of the RNA helix. Although the enzyme is thought to play a role in ribosomal RNA processing and gene regulation, the deletion of the rnc gene in S. aureus does not affect cel...

journal_title：Methods in enzymology

authors： Chevalier C,Huntzinger E,Fechter P,Boisset S,Vandenesch F,Romby P,Geissmann T

更新日期：2008-01-01 00:00:00

abstract：:A procedure for an in vitro signaling assay is described for the MAPK and NFkappaB pathways. The method uses a membrane-cleared lysate that contains all the soluble components required for activating these signaling cascades. The pathways can be activated by variety of molecules, including kinases, G-proteins, and E3 ...

journal_title：Methods in enzymology

authors： Mukherjee S,Orth K

更新日期：2008-01-01 00:00:00

abstract：:Rab38 is a low-molecular-weight G-protein highly expressed in melanocytes of the skin and alveolar type II cells in the lung. A point mutation in the postulated GTP/GDP-interacting domain of Rab38 has been identified as the genetic lesion responsible for oculocutaneous albinism (OCA) in chocolate (cht) mice. Another p...

journal_title：Methods in enzymology

authors： Osanai K,Voelker DR

更新日期：2008-01-01 00:00:00

abstract：:The RNA degradosome is a bacterial protein machine devoted to RNA degradation and processing. In Escherichia coli, it is typically composed of the endoribonuclease RNase E, which also serves as a scaffold for the other components: the exoribonuclease PNPase, the RNA helicase RhlB, and enolase. The variable presence of...

journal_title：Methods in enzymology

authors： Mauri P,Dehò G

更新日期：2008-01-01 00:00:00

abstract：:Guanine nucleotide exchange factors (GEFs) are essential regulators of the spatiotemporal conditions of small GTP-binding protein (SMG) activation. Their cellular activities combine the biochemical stimulation of GDP/GTP exchange, which leads to the active conformation of the SMG, to the detection of upstream signals ...

journal_title：Methods in enzymology

authors： Zeeh JC,Antonny B,Cherfils J,Zeghouf M

更新日期：2008-01-01 00:00:00

abstract：:Two-component signal transduction systems, composed of histidine kinases and response regulators, enable bacteria to sense, respond, and adapt to changes in their internal and external conditions. The importance of these signaling systems is reflected in their widespread distribution and prevalence in the bacterial ki...

journal_title：Methods in enzymology

authors： Laub MT,Biondi EG,Skerker JM

更新日期：2007-01-01 00:00:00

abstract：:The Rcs phosphorelay, consisting of a hybrid sensor kinase, a phosphotransferase, and a response regulator, regulates a large number of bacterial functions. These include capsule production, the target originally defined for these regulators, a small regulatory RNA, and a growing list of additional genes, many of unkn...

journal_title：Methods in enzymology

authors： Majdalani N,Gottesman S

更新日期：2007-01-01 00:00:00

abstract：:A fundamental concept of phosphorylation-mediated signaling is the precise switching between discrete functional conformations. According to the traditional view, phosphorylation induces a new, active conformation. In this chapter, a series of NMR experiments performed on a response regulator are described that challe...

journal_title：Methods in enzymology

authors： Gardino AK,Kern D

更新日期：2007-01-01 00:00:00

abstract：:Hypoxia and inflammation are coincidental events in an array of diseased tissues, including chronically inflamed sites (e.g., inflammatory bowel disease, rheumatoid arthritis), growing tumors, myocardial infarcts, atherosclerotic plaques, healing wounds, and sites of bacterial infection (Murdoch et al., 2005). An unde...

journal_title：Methods in enzymology

authors： Cummins EP,Comerford KM,Scholz C,Bruning U,Taylor CT

更新日期：2007-01-01 00:00:00

abstract：:Human solid tumors are invariably less well-oxygenated than the normal tissues from which they arose. This so-called tumor hypoxia leads to resistance to radiotherapy and anticancer chemotherapy as well as predisposing for increased tumor metastases. In this chapter, we examine the resistance of tumors to radiotherapy...

journal_title：Methods in enzymology

authors： Brown JM

更新日期：2007-01-01 00:00:00

abstract：:The hypoxia-inducible factor (HIF) is a heterodimeric basic helix-loop-helix (bHLH) transcription factor that controls the mammalian cellular transcriptional response to low oxygen tension by up-regulating genes including glycolytic enzymes and angiogenic factors, such as the vascular endothelial growth factor (VEGF)....

journal_title：Methods in enzymology

authors： Doedens A,Johnson RS

更新日期：2007-01-01 00:00:00

abstract：:In recent years, sphingolipid metabolites ceramide, sphingosine, and sphingosine-1-phosphate have emerged as important second messengers in addition to their role as precursors of biomembrane components. The investigation of these sphingolipid metabolites requires the development of new, more sensitive methods for ass...

journal_title：Methods in enzymology

authors： Spassieva S,Bielawski J,Anelli V,Obeid LM

更新日期：2007-01-01 00:00:00

abstract：:Phospholipase A(2)s (PLA(2)s) are a superfamily of enzymes involved in production of a wide variety of lipid mediators, including arachidonic acid, lysophospholipids, platelet activation factor, and eicosanoids. Fluorescence-based, real-time cellular activity assays for PLA(2)s have been developed as a tool for studyi...

journal_title：Methods in enzymology

authors： Manna D,Cho W

更新日期：2007-01-01 00:00:00

abstract：:The neutral arachidonic acid derivatives N-arachidonoyl ethanolamine (anandamide or AEA), and 2-arachidonoylglycerol (2-AG) have been identified as endogenous ligands for the cannabinoid receptors. Additionally, these compounds have been identified as substrates of the second isoform of the cyclooxygenase enzyme (COX-...

journal_title：Methods in enzymology

authors： Kingsley PJ,Marnett LJ

更新日期：2007-01-01 00:00:00

abstract：:This chapter outlines methods that can be applied to determine the levels of lipids in cells and tissues. In particular, the methods focus upon the extraction and analysis of those lipids critical for monitoring signal transduction pathways. The methods address the analysis of the phosphoinositides, the lipid agonists...

journal_title：Methods in enzymology

authors： Wakelam MJ,Pettitt TR,Postle AD

更新日期：2007-01-01 00:00:00

abstract：:Integrins are large modular cell-surface receptors that regulate almost every aspect of cellular function through bidirectional signals transmitted across the lipid bilayer. Regulation of integrin activity is accomplished by complex and still incompletely understood biochemical pathways that modify integrin ligand bin...

journal_title：Methods in enzymology

authors： Xiong JP,Goodman SL,Arnaout MA

更新日期：2007-01-01 00:00:00

abstract：:Integrin adhesion receptors mediate cell-cell and cell-substratum adhesion and provide a continuous link for the bidirectional transmission of mechanical force and biochemical signals across the plasma membrane. Integrin-dependent cellular activities such as adhesion, migration, proliferation, and survival rely upon t...

journal_title：Methods in enzymology

authors： Lad Y,Harburger DS,Calderwood DA

更新日期：2007-01-01 00:00:00

abstract：:Specific recognition of mRNA 5' cap by eukaryotic initiation factor eIF4E is a rate-limiting step in the translation initiation. Structural determination of the eIF4E-cap complexes, as well as complexes of eIF4E with other proteins regulating its activity, requires complementary experiments that allow for energetic an...

journal_title：Methods in enzymology

authors： Niedzwiecka A,Stepinski J,Antosiewicz JM,Darzynkiewicz E,Stolarski R

更新日期：2007-01-01 00:00:00

abstract：:In eukaryotes, translation initiation involves recruitment of ribosomal subunits at either the 5' m7G cap structure or at an internal ribosome entry site (IRES). For most mRNAs, the initiation codon is located some distance downstream, necessitating ribosomal movement to this site. Although the mechanistic details of ...

journal_title：Methods in enzymology

authors： Mauro VP,Chappell SA,Dresios J

更新日期：2007-01-01 00:00:00

abstract：:In vitro assembly of eukaryotic translation initiation complexes requires purification of ribosomal subunits, eukaryotic initiation factors, and initiator tRNA from natural sources and therefore yields only limited material for functional and structural studies. In this chapter, we describe a robust, affinity chromato...

journal_title：Methods in enzymology

authors： Locker N,Lukavsky PJ

更新日期：2007-01-01 00:00:00

abstract：:When isolating ribonucleoprotein (RNP) complexes by an affinity selection approach, tagging the RNA component can prove to be strategically important. This is especially true for purifying single types of snoRNPs, because in most cases the snoRNA is thought to be the only unique component. Here, we present a general s...

journal_title：Methods in enzymology

authors： Piekna-Przybylska D,Liu B,Fournier MJ

更新日期：2007-01-01 00:00:00

abstract：:Formation of 5-methyluridine (ribothymidine) at position 54 of the T-psi loop of tRNA is catalyzed by site-specific tRNA methyltransferases (tRNA[uracil-54,C5]-MTases). In eukaryotes and many bacteria, the methyl donor for this reaction is generally S-adenosyl-L-methionine (S-AdoMet). However, in other bacteria, like ...

journal_title：Methods in enzymology

authors： Urbonavicius J,Brochier-Armanet C,Skouloubris S,Myllykallio H,Grosjean H

更新日期：2007-01-01 00:00:00

abstract：:Rarely is any solution simply solute and water. In vivo, solutes, such as proteins and nucleic acids, swim in a sea of water, salts, ions, small molecules, and lipids, not to mention other macromolecules. In vitro, virtually all solutions contain a mixture of aqueous solvents, or "cosolvents" [i.e., solvent(s) in addi...

journal_title：Methods in enzymology

authors： Beck DA,Bennion BJ,Alonso DO,Daggett V

更新日期：2007-01-01 00:00:00

abstract：:Since the early days of cell volume regulation research, the role of actin cytoskeleton organization and rearrangement has attracted specific interest. Rapid modifications in actin dynamics and architecture have been described. They were shown to regulate cell volume changes, as well as regulatory volume decrease in a...

journal_title：Methods in enzymology

authors： Papakonstanti EA,Stournaras C

更新日期：2007-01-01 00:00:00

abstract：:Osmoregulation is the active control of the cellular water balance and encompasses homeostatic mechanisms crucial for life. The osmoregulatory system in the yeast Saccharomyces cerevisiae is particularly well understood. Key to yeast osmoregulation is the production and accumulation of the compatible solute glycerol, ...

journal_title：Methods in enzymology

authors： Hohmann S,Krantz M,Nordlander B

更新日期：2007-01-01 00:00:00

abstract：:MicroRNA (miRNA) genes are transcribed into long primary transcripts (pri-miRNAs) that get processed into mature miRNAs of about 22 nt in length by two different ribonuclease (RNase) III enzymes, Drosha and Dicer. Various experimental protocols have been developed and modified for genetic and biochemical analyses for ...

journal_title：Methods in enzymology

authors： Lee Y,Kim VN

更新日期：2007-01-01 00:00:00

abstract：:Natural products continue to demonstrate their utility both as therapeutics and as molecular probes for the discovery and mechanistic deconvolution of various cellular processes. However, this utility is dampened by the inherent difficulties involved in isolating and characterizing new bioactive natural products, in o...

journal_title：Methods in enzymology

authors： Low WK,Dang Y,Schneider-Poetsch T,Shi Z,Choi NS,Rzasa RM,Shea HA,Li S,Park K,Ma G,Romo D,Liu JO

更新日期：2007-01-01 00:00:00

abstract：:For mRNAs encoding secretory and integral membrane proteins, translation initiation is thought to begin a process of mRNA localization where mRNA/ribosome/nascent chain complexes (RNCs) are trafficked from the cytosol compartment to the endoplasmic reticulum (ER). At the ER membrane, RNCs bind to a protein-conducting ...

journal_title：Methods in enzymology

authors： Stephens SB,Nicchitta CV

更新日期：2007-01-01 00:00:00

abstract：:The properties of a collection of transposon Tn5 derivatives that generate reporter gene fusions and internal protein tags are summarized. Procedures utilizing several of the transposons for generating genes activated by Cre-loxP recombination and for creating large sequence-defined mutant libraries are described in d...

journal_title：Methods in enzymology

authors： Gallagher L,Turner C,Ramage E,Manoil C

更新日期：2007-01-01 00:00:00

abstract：:One of the greatest advances in molecular genetics has been the application of selectable transposons in molecular biology. After 30 years of use in microbial genetics studies, transposons remain indispensable tools for the generation of null alleles tagged with selectable markers, genetic mapping, manipulation of chr...

journal_title：Methods in enzymology

authors： Maloy SR

更新日期：2007-01-01 00:00:00