"Two-component" phosphorelay signal transduction systems constitute a potential target for antibacterial and antifungal agents, since they are found exclusively in prokaryotes and lower eukaryotes (yeast, fungi, slime mold, and plants) but not in mammalian organisms.(omitted)

The control mechanism of cellular functions has been classified into two modes: one rapid mechanism occurring within minutes by kinetic alterations of effector proteins without changing the number of effector molecules and another slow mechanism occurring over hours and days by changes in the number of effector molecules without kinetic alterations.(omitted)

Almost half of the entire set of predicted genomic products from M ethanococcus jannaschii are classified as functionally unknown hypothetical proteins. We present a structure-based identification of the biochemical function of a protein with hitherto-unknown function from a M. jannaschii gene, Mj0226.(omitted)

A sweet protein monellin was originally isolated from the berries of the West African plant Dioscoreophyllum cumminsii. The studies for molecular interaction of different sweeteners with receptor as well as receptor binding model have been proposed previously. The high-resolution solution structure of single-chain monellin (SCM) has been determined to investigate structural origin of sweet taste by NMR spectroscopy and simulated annealing calculations.(omitted)

The functions and the medicinal values of peptides are closely related to their structures. Most of the peptides function in the mediation of the membrane. Biological membrane serves important functions in the binding of peptide to a membrane-embedded receptor.(omitted)

Bacterial chemotaxis receptors are some of the simplest and most studied transmembrane receptors. Their simple signaling pathway has elements relevant for understanding the mechanisms for signal recognition, transduction through the membrane, relays among the molecules in the pathway, and adaptation to a persistent signal.(omitted)

A signal of Fas-mediated apoptosis is transferred through an adaptor protein FADD by interactions between death domains of Fas and FADD. To understand the signal transduction mechanism of Fas-mediated apoptosis, we solved the solution structure of a murine FADD death domain.(omitted)

Voltage-gated $K^{＋}$ channels represent the most complex group of ion channel genes expressed in cardiovascular system. The human Kv1.5 channel (hKv1.5) represents the $I_{Kur}$ repolarizing current in atrial myocytes. The hKv1.5 channel is functionally modulated by the Kv$\beta$1.3 subunit, which converts it from a delayed rectifier to a channel with rapid inactivation and enhanced voltage sensitivity.(omitted)d)

Intracellular pH(pH$_{i}$) regulation is very important to regulate the cellular functions of cardiac myocytes such as contractility, signal transduction, ion regulation, cell volume, and energy production etc. The resting pH$_{i}$ was maintained at about 7.07 and strictly regulated within the range of $\pm$0.1.(omitted)ted)

Ionic currents through many different cation channels are specifically reduced by internal and/or external $Mg^{2＋}$ within a concentration range of physiological relevance. Although there are many ways for a divalent cation to reduce channel currents, the current blockade by directly binding to a conduction pore has been most well studied.(omitted)

The movement of water across cell plasma membranes occurs in all cell types but is particularly rapid in erythrocytes, renal tubular cells. In principle, osmotic/oncotic gradients and hydrostatic pressure difference can drive water across a cell layer by transcellular or paracellular pathways. The aquaporin family of molecular water channels, which now number 10 in mammals and many more in plants and lower organism, are likely to provide a molecular pathway for water transport in some cell membranes.(omitted)

Diabetic cardiomyopathy has been suggested to be caused by the intracellular Ca$\^$2＋/ overload in the myocardium. We have investigated the possible mechanism of the functional defect of cardiac sarcoplasmic reticulum (SR) in diabetic rats with respect to Ca$\^$2＋/-ATPase and phospholamban (PLB) at the transcriptional and translational levels.(omitted)

Neuropeptide ${\gamma}$ is a recently identified tachykinin family peptide which has conserved ammo acid sequence of -Phe-X-Gly-Leu-Met-NH2 in the C-terminal region, where X represents aromatic or hydrophobic residues. In this study, three-dimensional structure of neuropeptide ${\gamma}$ from goldfish Carassius auratus (G-NP${\gamma}$) was determined by NMR spectroscopy.(omitted)

Cecropin A(1-8)-magainin 2(1-12) and cecropm A(1-8)-melittin(1-12) hybrid peptides were known to have potent antitumor and antibacterial activity. In particular, cecropm A(l-8)-magainin 2(1-12) has powerful antibacterial and antitumor activity with no hemolytic effect.(omitted)

Mastoparan B (MP-B), an antimicrobial cationic tetradecapeptide amide isolated from the venom of the hornet Vespa basalis, is an amphiphilic ${\alpha}$-helical peptide. In order to study the relationship between the structure and biological activity, we used the three analogues by replacing amino acids with alanine (4LysAla： 4MP-B, 12-LYsAla: 12MP-B, 9TrpAla: 9Mp-B).(omitted)

TRAIL (also known as Apo-2L) is a newly identified cytokine belonging to the large tumor necrosis factor (TNF) family. TRAIL is a novel molecule in that it induces apoptosis in a wide variety of tumor cells but not in normal cells. In order to help elucidating its biological roles and designing mutants with improved therapeutic potential, we have determined the crystal structure of human TRAIL.(omitted)

Amylases catalyze the hydrolysis of starch material and play central roles in carbohydrate metabolism. The structure and a size exclusion column chromatography proved that the enzyme is a dimer in solution. The N -terminal segment of the enzyme folds into a distinct domain and comprises the enzyme active site together with the central (${\alpha}$/ ${\beta}$)$\sub$8/ barrel of the adjacent subunit.(omitted)

Bacterial Δ-3-ketosteroid isomerase (KSI) catalyzes the conversion of Δ-to Δ-3-ketosteroids via enolate formation, which is also found in the synthesis of all steroid hormones in mammals. In Pseudomonas testosteroni, KSI Asp38 (pKa ~ 4.7) was identified as the general base which abstracts the steroid C4b-H (pKa ~ 12.7) to form the dienolate intermediate.(omitted)

The influenza A viruses which are the most severe and common among the influenza viruses have 8 segmented RNA genomes Each RNA segment has highly conserved 3' and 5' terminal sequence except a single U\longrightarrowC variation especially in the 4 position of the 3' terminal of the 3 segments encoding own RNA polymerase.(omitted)

Calculations on conformational free energies of Ac-Pro-NHMe and its $C^{\delta}$-methylated derivatives have been carried out with the higher levels of quantum-chemical methods to figure out the cis-trans isomerization of the imide bond of proline and $C^{\delta}$-methylated prolines in the gas phase and in solution.(omitted)hase and in solution.(omitted)

Single chain-monellin (SCM) was recently constructed by fusing the two chains of monellin. From the view of protein folding, SCM serves as an ideal model system especially in tackling ${\alpha}$-helix-${\beta}$-sheet interactions due to the following reasons： First, it consists of simple distinct structural elements (${\alpha}$-helix and ${\beta}$-sheet) which are assembled in a perpendicular manner.(omitted)

We propose a method where interaction energies and force components are calculated separately for each residue of biomolecules. It is found that the correlation factors obtained from the analysis of five types of force terms and one interaction energy term (main chain self-energy) can be used to predict a mutants free energy difference relative to wild type.(omitted)

The native forms of some proteins such as inhibitory serpins (serine protease inhibitors) and viral membrane fusion proteins are metastable, which is critical to their functions. To understand the mechanism of how native metastability regulates the inhibitory function of serpins, we characterized stabilizing mutations of $\alpha$$_1$-antitrypsin, a prototype serpin, in which Gly 117 was replaced by a series of larger hydrophobic residues.(omitted)

Metastability in the native form of proteins has been recognized as a mechanism of biological regulation. The strained native structure of serpins (serine proteinase inhibitors) is a typical example. The native strain of serpins is considered to be crucial to their physiological functions, such as plasma proteinase inhibition, hormone delivery, Alzheimer filament assembly, and extracellular matrix remodeling.(omitted)

Signal peptides of secretary proteins interact with various membranes and non-membrane components during the translocation. We investigated the interaction of signal peptides of ribose binding protein (RBP) with Escherichia coli (E.coli) signal recognition particle (SRP), SecA and lipid bilayer. Previous studies showed that the functional signal peptides inhibit the GTPase activity of E.coli SRP which consisted of F로 and 4.5S RNA.(omitted)

Yeast cytochrome c peroxidase (CcP) was cloned and overexpressed in E. coli, and purified by a Ni$^{2＋}$-affinity column. HoloCcP was obtained by reconstituting apoCcP with Mn$^{3+}$-protoporphyrin IX (MnPP). Electron paramagnetic resonance (EPR) spectra of spin-labeled holoCcP showed a slightly more immobilized signal than spin-labeled apoCcP.(omitted)

Cytochrome c (cyt c) binds to acidic membranes at low ionic strength. Replacement of Lys-72 or Lys-87 by Glu reduced the binding affinity of cyt c toward large unilamellar vesicles (LUV) in liquid crystalline phase. The differences were smaller for LUV in gel phase. A fraction of bound cyt c was non-electrostatically associated.(omitted)

Positively charged cytochrome c interacts with the negatively charged mitochondrial inner membrane. This interaction induces conformational changes in bound cytochrome c. In order to estimate the effect of cytochrome c-membrane interaction on the mitochondrial electron transfer, we have investigated oxidation of ferrocytochrom c in the presence of anionic phospholipids.(omitted)

Tolaasin is a bacterial paptide toxin which is produced by Pseudomonas tolaasii. It forms pores in the cellular membranes, causing the brown blotch disease on the cultivated oyster mushroom. Previously, we showed that tolaasin-induced pore formation required the multimerization of tolaasin molecules. In order to measure the ionic effect on the tolaasin multimerization, the time course of tolaasin-induced hemolysis was measured in the presence of various cations and anions.(omitted)

Two types of vanadate-sensitive $Ca^{2＋}$-ATPases have been characterized in the microsomes of tracheal epithelial cells, a high affinity vanadate-sensitive (HA VS) and a low affinity vanadate-sensitive (LAVS) $Ca^{2＋}$-ATPases. The LA VS $Ca^{2＋}$-ATPase was sensitive to thapsigargin, implying that it is an ER/SR-type $Ca^{2+}$-ATPase.(omitted)d)

$H^{＋}$-ATPases play major roles in various cellular physiology. In order to characterize the effects of heavy metal ions on the activity of $H^{＋}$-ATPases, microsomes were isolated from the roots of tomato grown hydroponically. The activity of microsomal $H^{＋}$-ATPase was measured by an enzyme-coupled assay. H $g^{2＋}$ inhibited the activity of microsomal $H^{+}$-ATPase as a dose-dependent manner, F $e^{3+}$ and Z $n^{2+}$ inhibited the activity although they also blocked the activities of enzymes used in the assay, and C $s^{+}$ and $Ba^{2+}$ showed no significant effect.(omitted)d)ted)d)

The mammalian cortical collecting duct (CCD) plays a major role in regulating renal NaCl absorption, which is important in controlling total body Na and Cl homeostasis. The M-1 cell line, derived from the mouse cortical collecting duct, is being used as a mammalian model of the CCD to study electrolytes transport.(omitted)

Polyamines are polyvalent cations which are ubiquitously present in pro- and eukaryotic cells. In the present study we investigated the action mechanism of spermine$\^$＋4/ (C$\sub$10/), a natural polyamine, on the large-conductance Ca$\^$2＋/-activated K (maxi-K) channel using excised patches from the human gastric smooth muscle.(omitted)

Inactivation of N-type calcium current has been reported to be voltage dependent (Jones ＆ Marks, 1989) and $Ca^{2＋}$ dependent(Cox ＆ Dunlap, 1994). We examined inactivation by recording currents from the same cell both in [B $a^{2＋}$]$_{o}$ and [C $a^{2＋}$]$_{o}$ in rat sympathetic neurons. With 11 mM internal EGTA, fractional inactivation[l-(current amplitude at the end of 5 sec pulse/peak current amplitude [1-(current amplitude at the end of 5 sec pulse/peak current amplitude)] was larger in $Ca^{2+}$(0.80$\pm$0.07) than in $Ba^{2+}$(0.69$\pm$0.10)(n=31, p<0.001), but the current traces were nicely fitted with two exponential components both in $Ba^{2+}$ and $Ca^{2+}$.(omitted)ted)ted)

We have investigated whether alterations in the expression levels of sarcoplasmic reticulum (SR) $Ca^{2＋}$ regulatory proteins in heart and mesenteric arteries from different models of hypertension would occur. Nephrectomied diabetic-hypertensive rats (DM-HT) and spontaneously hypertensive rats (SHR) were used as models of hypertension.(omitted)

Protein kinase modulation of gamma-aminobutyric acid C (GABA$_{c}$) currents in freshly dissociated catfish retinal cone-horizontal cell axon-terminals was studied under voltage clamp with the use of the whole cell patch-clamp technique. Responses to pulses of GABA were monitored in intracellular application of adenosin 3',5'-cycle monophophate (cAMP)-dependent protein kinase (PKA) and protein kinase C (PKC) activators, and their inhibitors or inactive analogues.(omitted)d)

Imperatoxin A (IpTx$_{a}$), a 3.7 kDa peptide from the African scorpion Pandinus imperator, has been known as an agonist of skeletal ryanodine receptor (RyR). In order to study the structure and function of the toxins on RyR, the IpTx$_{a}$ cDNA was PCR-amplified using 3 pairs of primers and the toxin was expressed in E. coli expression system.(omitted)ted)

Change of membrane property can affect the activity of membrane proteins. In this work, we investigated the single channel properties of large conductance $Ca^{2+}$-activated $K^{+}$(BK) channels in planar lipid bilayers of different thickness. First, we recorded the activity of single BK channels from rat skeletal muscle incorporated into the control bilayer, then increased the bilayer thickness by perfusing the recording solution with the one saturated with n-pentane, or reduced the thickness by adding diheptanoylphosphatidylcholine (di$C_{7:0}$PC) to the recording soluton.(omitted)

It is well known that rapidly activating delayed rectifier $K^{＋}$ channels ( $I_{Kr}$ ) playa role in repolarisation in mammalian hearts. Recently, human ether-a- go- go related gene (HERG) channels was shown to be a molecular equivalent to $I_{Kr}$ . We have investigated the permeation of various external cations on $I_{Kr}$ in mammalian hearts and on HERG channels expressed in Xenopus laevis oocytes.(omitted)

The paraventricular nucleus (PVN) is a complex structure comprised of several different populations of cells divided into two main groups, the magnocellular (type I) neurons which secrete vasopressin and oxytocin and the parvocellular (type II) neurons which regulate hormone secretion from the anterior pituitary.(omitted)

Circulating substances can directly access the neurons in circumventricular organ (CVO) located on the border of cerebral ventricles. The neurons in CVO are considered to playa pivotal role in blood-brain communication. In subfonical organ (SFO), a CVO in forebrain, angiotensin II (AII) is mown to reduce A type $K^{＋}$ current and input resistance, but enhance firing rate.(omitted)

The subfornical organ (SFO) represents neuroglial circumventricular organ structures bordering the anterior third cerebral ventricle. Owing to the absence of the blood-brain barrier, the cellular elements of subfornical organ can be reached by circulating messenger molecules transferring afferent information and provide a good coding model of chemical information processing in the body.(omitted)

;The mechanisms inducing hypertension are actively investigated and are still challenging topics. Basically hypertension must be caused by the disorder of $Ca^{2+}$ metabolism in vascular smooth muscle, such as the increase of $Ca^{2+}$ influx, the decrease of ci+ efflux, or the change of sensitivity of contractile protein etc. The one of cause of the increase of ci+ influx may be the change of ci+ channel activity. Even though the relationships of ci+ channel activity and hypertension were studied using various hypertension models, still it is not clear how much change of $Ca^{2+}$ channel activity in diabetes mellitus (DM) induced hypertension is occurred. We induced DM hypertension in SD rat and compared the $Ca^{2+}$ channel activity with age-matched normotensive SD rat. For inducing DM hypertension, left kidney was removed with 200 gm rat and, after 1 month, 60 mg/kg of streptozotocin was injected into peritoneal space to induce diabetes mellitus. Usually after 4-6 weeks, hypertension was fully induced. For isolating vascular smooth muscle cells (VSMC), we used mesenteric arteriole (3rd - 4th branch of mesenteric artery) of which diameter is below 150 urn. VSMCs were isolated enzymatically. $Ca^{2+}$ current was measured using whole cell patch clamp technique. All experiments were performed at $37^{\circ}C$. The cell membrane area of VSMC of DM hypertensive rat is larger than that of control VSMC($36.6{\pm}3.64{\;}pF{\;}vs{\;}22.4{\pm}1.29{\;}pF, {\;}mean{\pm}S.E.$) When we compared the current amplitude, the $Ca^{2+}$ current amplitude in VSMC of DM hypertensive rat is much larger than that in VSMC of normotensive age-matched rat. After $Ca^{2+}$ current amplitude was normalized by cell membrane area, the current amplitude in DM hypertension is increased to $249.1{\pm}15.9{\;}%{\;}(mean{\pm}S.E.M)$, which means the ;absolute current amplitude is about 4 times larger in DM hypertension. When we compared the steady state activation and inactivation. there were no noticeable differences. From these results. one of cause of the DM hypertension is due to the increase of $Ca^{2+}$ current amplitude. But it need further study why the $Ca^{2+}$ current is so large in VSMC of DM hypertension and how much $Ca^{2+}$ influx through $Ca^{2+}$ channel contribute to the increase of intracellular $Ca^{2+}$ and eventually contribute to development of hypertension.ypertension.

Large conductance $Ca^{2＋}$-activated $K^{＋}$ channels (Maxi-K channel) have been implicated in many important physiological processes such as co-ordination of membrane excitability in neurons. Modulation of these channels are archived by the activity of various protein kinases. The most widely studied example of Maxi-K channel regulation by protein phosphorylation has been obtained using plasma membranes from the rat brain incorporated into lipid bilayers.(omitted)

Amitriptyline has been known to induce QT prolongation and ventricular arrhythmias such as torsades de pointes which causes sudden death. We studied the effects of amitriptyline on the human ether-a-go-go-related gene (HERG) channel expressed in Xenopus oocytes.(omitted)

Na$^{＋}$-Ca$^{2＋}$ Exchanger is known to playa critical role in the regulation of intracellular $Ca^{2＋}$ in many tissues and cells. In heart, the Na$^{＋}$-Ca$^{2＋}$ exchange is the principal $Ca^{2＋}$ extrusion mechanism and affects cardiac excitation-contraction coupling. To understand the functional role of cardiac Na$^{＋}$ -Ca$^{2＋}$ exchanger (NCXl) in vivo, we tried to ablate the cardiac Na$^{2+}$-Ca$^{2+}$ exchanger gene locus by the use of the gene targeting technologies.(omitted)ted)

The negative chronotropic effect of ACh on heart fades in the continuous presence of ACh, which is known as a phenomenon called "vagal escape". The underlying mechanism of vagal escape is not entirely clear, but desensitization of acetylcholine-activated $K^{＋}$ currents ($K_{ACh}$) was suggested, at least in part, to be responsible.(omitted)d)

The effect of chlorpromazine on the store-operated Ca$\^$2＋/ entry subsequently activated via the phospholipase C signaling pathway was investigated in PC12 cells. Chlorpromazine caused a rapid decline of the bradykinin-induced Ca$\^$2＋/ increase to basal level without attenuating the peak level.(omitted)

Extracellular A TP is known to function as a neurotransmitter and as a modulator in the variety of cell types. In PC12 cells, extracellular A TP elevates [Ca$\^$2＋/]j through receptor-operated Ca$\^$2＋/ channels and through the activation of phospholipase C, thereby facilitating the secretion of neurotransmitters.(omitted)

The human genetic disorder ataxia-telangiectasia (A-T) is a multisystem disease characterized by extreme radiosensitivity. The recent identification of the gene mutated in A-T, ATM, and the demonstration that it encodes a homologous of phosphatidylinositol 3-kinase (PI3-K), the catalytic subunit of an enzyme involved in transmitting signals from the cell surface to the nucleus, provides support for a role for this gene in signal transduction.(omitted)

Experimental studies have implicated the wild type p53 in cellular response to radiation. Whether altered p53 function can lead to changes in clinical radiocurability remains an area of ongoing study. This study was performed to investigate whether any correlation between change of p53 and outcome of curative radiation therapy in patients with head and neck cancers.(omitted)