TmcN is involved in ATP regulation of tautomycetin biosynthesis in Streptomyces griseochromogenes

2016 ◽  
Vol 478 (1) ◽  
pp. 221-226
Author(s):  
Ming Li ◽  
Yang Chen ◽  
Sijin Wu ◽  
Yan Tang ◽  
Ying Deng ◽  
...  
Keyword(s):  
Atp Regulation

Breast Cancer Resistance Protein: A Potential Therapeutic Target for Cancer

2020 ◽  
Vol 21 ◽  
Author(s):  
Sonali Mehendale-Munj
Keyword(s):  
Breast Cancer ◽  
Breast Cancer Resistance Protein ◽  
Protein A ◽  
The Body ◽  
Cancer Therapies ◽  
Cancer Resistance ◽  
Lung Cancers ◽  
Resistance Protein ◽  
Atp Regulation ◽  
Treatment Procedures

: Breast Cancer Resistance Protein (BCRP) is an efflux transporter responsible for causing multidrug re-sistance(MDR). It is known to expel many potent antineoplastic drugs, owing to its efflux function. Efflux of chemothera-peutics because of BCRP develops resistance to manydrugs, leading to failure in cancer treatment. BCRP plays an important role in physiology by protecting the organism from xenobiotics and other toxins. It is a half-transporter affiliated to theATP-binding cassette (ABC) superfamily of transporters, encoded by the gene ABCG2 and functions in response to adenosine triphosphate (ATP). Regulation of BCRP expression is critically controlled at molecular levels which help in maintaining the balance of xenobiotics and nutrients inside the body. Expression of BCRP can be found in brain, liver, lung cancers and acute myeloid leukemia (AML). Moreover, it is also expressed at high levels in stem cells and many cell lines. This frequent expression of BCRP has an impact on the treatment procedures and if not scrutinized may lead to failure of many cancer therapies.

Altered brain phosphocreatine and ATP regulation when mitochondrial creatine kinase is absent

2001 ◽  
Vol 66 (5) ◽  
pp. 866-872 ◽  
Author(s):  
T�a Kekelidze ◽  
Igor Khait ◽  
Anthony Togliatti ◽  
Jorge M. Benzecry ◽  
Be Wieringa ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Mitochondrial Creatine Kinase ◽  
Atp Regulation

In squid nerves intracellular Mg2+promotes deactivation of the ATP-upregulated Na+/Ca2+ exchanger

2000 ◽  
Vol 279 (5) ◽  
pp. C1631-C1639 ◽  
Author(s):  
Reinaldo DiPolo ◽  
Graciela Berberián ◽  
Luis Beaugé
Keyword(s):  
Metabolic Pathway ◽  
Membrane Vesicles ◽  
Nerve Membrane ◽  
Bovine Heart ◽  
Mammalian Heart ◽  
Atp Concentration ◽  
Phosphatidylinositol 4 ◽  
Atp Regulation

We investigated the role of intracellular Mg2+(Mgi 2+) on the ATP regulation of Na+/Ca2+ exchanger in squid axons and bovine heart. In squid axons and nerve vesicles, the ATP-upregulated exchanger remains activated after removal of cytoplasmic Mg2+, even in the absence of ATP. Rapid and complete deactivation of the ATP-stimulated exchange occurs upon readmission of Mgi 2+. At constant ATP concentration, the effect of intracellular Mg2+ concentration ([Mg2+]i) on the ATP regulation of exchanger is biphasic: activation at low [Mg2+]i, followed by deactivation as [Mg2+]i is increased. No correlation was found between the above results and the levels of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5) P 2] measured in nerve membrane vesicles. Incorporation of PtdIns(4,5) P 2 into membrane vesicles activates Na+/Ca2+ exchange in mammalian heart but not in squid nerve. Moreover, an exogenous phosphatase prevents MgATP activation in squid nerves but not in mammalian heart. It is concluded that 1) Mgi 2+ is an essential cofactor for the deactivation part of ATP regulation of the exchanger and 2) the metabolic pathway of ATP upregulation of the Na+/Ca2+ exchanger is different in mammalian heart and squid nerves.

Extracellular ATP regulates transcervical permeability by modulating two distinct paracellular pathways

1997 ◽  
Vol 272 (5) ◽  
pp. C1602-C1610 ◽  
Author(s):  
G. I. Gorodeski ◽  
J. Goldfarb
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Extracellular Atp ◽  
Acetoxymethyl Ester ◽  
Experimental Conditions ◽  
Mucus Production ◽  
Atp Regulation ◽  
Junctional Resistance ◽  
Kinetics Of

Extracellular ATP stimulates a biphasic change in transepithelial electrical resistance (RTE) across cultures of human cervical epithelial cells: an acute decrease (phase I), followed by a delayed increase in resistance (phase II). The objective of this study was to determine the contributions of changes in the lateral intercellular space resistance (RLIS) and the tight junctional resistance (RTJ) to the changes in RTE. Phase I and phase II effects were uncoupled by treatment with 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA)-acetoxymethyl ester, which blocks the ATP-induced increases in cytosolic Ca2+ and abolishes phase I. BAPTA-loaded cells differed from control cells in that 1) phase I began when ATP was added, in contrast to a delay of 1.5-3.5 min in phase II, 2) phase I decreases in RLIS followed a simple exponential pattern, in contrast to the complex kinetics of phase II, and 3) the magnitude of phase II varied between 20 and 100% for increases of RTJ in day 2-6 cultures; the phase I decrease of 50% in RLIS was unrelated to different experimental conditions. These results indicate that phase I and phase II are induced simultaneously and independently by ATP, and they contribute to the total changes in RTE. We conclude that ATP regulation of RLIS and RTJ may be important mechanisms of modulating cervical mucus production in vivo.

ATP regulation of the ligand-binding properties in temperate and cold-adapted haemoglobins. X-ray structure and ligand-binding kinetics in the sub-Antarctic fish Eleginops maclovinus

2012 ◽  
Vol 8 (12) ◽  
pp. 3295 ◽  
Author(s):  
Daniela Coppola ◽  
Stefania Abbruzzetti ◽  
Francesco Nicoletti ◽  
Antonello Merlino ◽  
Alessandra Gambacurta ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Antarctic Fish ◽  
Binding Kinetics ◽  
Binding Properties ◽  
Cold Adapted ◽  
X Ray ◽  
Eleginops Maclovinus ◽  
Atp Regulation

In vivo brain phosphocreatine and ATP regulation in mice fed a creatine analog

1997 ◽  
Vol 272 (5) ◽  
pp. C1567-C1577 ◽  
Author(s):  
D. Holtzman ◽  
R. Meyers ◽  
E. O'Gorman ◽  
I. Khait ◽  
T. Wallimann ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Ex Vivo ◽  
Competitive Inhibitor ◽  
High Energy ◽  
Energy Deficit ◽  
Resonance Spectroscopy ◽  
Atp Metabolism ◽  
Creatine Transport ◽  
Atp Regulation

Mitochondrial and cytosolic creatine kinase (CK) isozymes are active in cells with high and variable ATP metabolic rates. beta-Guanidinopropionic acid (GPA), a competitive inhibitor of creatine transport, was used to study the hypothesis that the creatine-CK-phosphocreatine (PCr) system is important in regulating brain ATP metabolism. The CK-catalyzed reaction rate and reactant concentrations were measured in vivo with 31P nuclear magnetic resonance spectroscopy during energy deficit (hypoxia) or high-energy turnover (seizures) states in urethane-anesthetized mice fed GPA, creatine, or standard chow (controls). Brain phosphagen (i.e., cellular energy reserves) or PCr plus phosphorylated GPA (GPAP) concentrations were equal. The phosphagen-to-NTP ratio was lower than in controls. In vivo CK reaction rate decreased fourfold, whereas ex vivo CK activity that was biochemically measured was doubled. During seizures, CK-catalyzed fluxes increased only in GPA-fed mice. Phosphagen increased in GPA-fed mice, whereas PCr decreased in controls. Survival was higher and brain phosphagen and ATP losses were less for hypoxic GPA-fed mice than for controls. In contrast to mice fed GPA, hypoxic survival and CK reactant concentrations during hypoxia and seizures were the same in creatine-fed mice and controls. Thus GPA, GPAP, or adaptive changes in ATP metabolism stabilize brain ATP and enhance survival during hypoxia in mice.

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