Search results for " Regulation"
showing 10 items of 3187 documents
CitA/CitB Two-Component System Regulating Citrate Fermentation in Escherichia coli and Its Relation to the DcuS/DcuR System In Vivo
2011
ABSTRACT Citrate fermentation by Escherichia coli requires the function of the citrate/succinate antiporter CitT ( citT gene) and of citrate lyase ( citCDEFXG genes). Earlier experiments suggested that the two-component system CitA/CitB, consisting of the membrane-bound sensor kinase CitA and the response regulator CitB, stimulates the expression of the genes in the presence of citrate, similarly to CitA/CitB of Klebsiella pneumoniae . In this study, the expression of a chromosomal citC-lacZ gene fusion was shown to depend on CitA/CitB and citrate. CitA/CitB is related to the DcuS/DcuR two-component system which induces the expression of genes for fumarate respiration in response to C 4 -di…
Genetic organization of the citCDEF locus and identification of mae and clyR genes from Leuconostoc mesenteroides.
1999
ABSTRACT In this paper, we describe two open reading frames coding for a NAD-dependent malic enzyme ( mae ) and a putative regulatory protein ( clyR ) found in the upstream region of citCDEFG of Leuconostoc mesenteroides subsp. cremoris 195. The transcriptional analysis of the citrate lyase locus revealed one polycistronic mRNA covering the mae and citCDEF genes. This transcript was detected only on RNA prepared from cells grown in the presence of citrate. Primer extension experiments suggest that clyR and the citrate lyase operon are expressed from a bidirectional A-T-rich promoter region located between mae and clyR.
Cytotoxicity of cucurbitacin E from Citrullus colocynthis against multidrug-resistant cancer cells
2019
Abstract Background Cucurbitacin E (CuE) is an oxygenated tetracyclic triterpenoid isolated from the fruits of Citrullus colocynthis (L.) Schrad. Purpose This study outlines CuE's cytotoxic activity against drug-resistant tumor cell lines. Three members of ABC transporters superfamily, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and ABCB5 were investigated, whose overexpression in tumors is tightly linked to multidrug resistance. Further factors of drug resistance studied were the tumor suppressor TP53 and the epidermal growth factor receptor (EGFR). Methods Cytotoxicity assays (resazurin assays) were used to investigate the activity of Citrullus colocynthis and CuE towar…
Polyamines in Developing Stress-Resistant Crops
2012
F.Marco,R.Alcazar,T.Altabella,P.Carrasco,SarvajeetSinghGill,NarendraTuteja,andA.F. TiburcioPolyamines (PAs) are small protonated compounds with key roles in plant devel-opmentandphysiologicalprocesses.PAsmayalsofunctionasstressmessengersinplant responses to different stress signals. Recent studies using exogenous appli-cation of polyamines and more contemporary genetic manipulation of polyaminelevelsincropsandmodelspeciespointtotheirinvolvementinstressprotection.Thedifferentmechanismsbywhichpolyaminesexerttheirfunctionsarepresentlybeingunraveledandinvolvedifferentmodesofactionthataresummarizedinthischapter.Polyamines are integrated with other stress-related hormone pathways, such asabscisic…
Ricerche in tema di società questuarie
2019
Intorno al regime delle società di tipo questuario – riconducibili agli schemi teorici della societas universorum quae ex quaestu veniunt – e delle società unius alicuius negotiationis e unius rei, si profusero gli sforzi interpretativi dei giuristi romani, fin dalla fine dell’età repubblicana. La monografia scientifica ripercorre le tracce della individuazione della nozione stessa di quaestus (guadagno), con particolare riferimento alla inclusione al suo interno delle donazioni cd. remuneratorie; ancora, ricostruisce il dibattito giurisprudenziale sorto intorno alla questione se i soci – nella determinazione delle quote – dovessero rispettare una proporzione rispetto ai conferimenti, con u…
Absorptive Capacity and Social Capital: Innovation and Environmental Regulation
2010
Norwegian paper and pulp mills are subject to strict environmental regulation. The mills conduct research and development for reducing pollution. Absorptive capacity indicates their competence. Firms are part of a social network of connections with external actors that include other paper and pulp mills, suppliers, customers, research institutes, and universities that help them in developing technologies. These relations represent their social capital. Some firms have access to more and better resources than other firms. Measuring firms’ absorptive capacity and access to social capital, we analyze their success in reducing pollution levels. There is a strong interaction effect between absor…
Diverse stress signals activate the C1 subgroup MAP kinases ofArabidopsis
2007
AbstractMitogen-activated protein kinase (MAPK) cascades play an important role in mediating stress responses in plants. In Arabidopsis, 20 MAPKs have been identified and classified into four major groups (A–D). Little is known about the role of group C MAPKs. We have studied the activation of Arabidopsis subgroup C1 MAPKs (AtMPK1/AtMPK2) in response to mechanical injury. An increase in their kinase activity was detected in response to wounding that was blocked by cycloheximide. Jasmonic acid (JA) activated AtMPK1/AtMPK2 in the absence of wounding. Wound and JA-induction of AtMPK1/2 kinase activity was not prevented in the JA-insensitive coi1 mutant. Other stress signals, such as abscisic a…
Integration of polyamins in the cold acclimation response
2011
8 páginas, 1 figura, 3 tablas -- PAGS nros. 31-38
Isoquercitrin and polyphosphate co-enhance mineralization of human osteoblast-like SaOS-2 cells via separate activation of two RUNX2 cofactors AFT6 a…
2014
Isoquercitrin, a dietary phytoestrogen, is a potential stimulator of bone mineralization used for prophylaxis of osteoporotic disorders. Here we studied the combined effects of isoquercitrin, a cell membrane permeable 3-O-glucoside of quercetin, and polyphosphate [polyP], a naturally occurring inorganic polymer inducing bone formation, on mineralization of human osteoblast-like SaOS-2 cells. Both compounds isoquercitrin and polyP induce at non-toxic concentrations the mineralization process of SaOS-2 cells. Co-incubation experiments revealed that isoquercitrin (at 0.1 and 0.3μM), if given simultaneously with polyP (as Ca(2+) salt; at 3, 10, 30 and 100μM) amplifies the mineralization-enhanci…
Mobile Phone Data Statistics as Proxy Indicator for Regional Economic Activity Assessment
2019
The mobile data analysis is an authoritative source of information for problems solving in the fields of human activity recognition, population dynamics, tourism, transport planning, traffics measuring, public administration and other activities and could be the source for valuable information as a proxy indicator. One of the obstacles to user data from mobile operators is compliance to the General Data Protection Regulation, so the development of data analytics approach that protects personal data without a necessity to identify mobility of particular persons was developed, that still provides economically relevant data. In the present research, the method for the economic activity assessm…