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Medinets Sergiy Gasche Rainer Kiese Ralf Rennenberg Heinz Butterbach-Bahl Klaus 《Plant and Soil》2019,445(1-2):335-348
Plant and Soil - Soils are known to be significant sources of atmospheric nitric oxide (NO), a key compound in atmospheric chemistry. NO is a key regulating substance for inter- and intra-species... 相似文献
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In vivo functions of mitogen-activated protein kinases: conclusions from knock-in and knock-out mice 总被引:4,自引:0,他引:4
Multicellular organisms achieve intercellular communication by means of signalling molecules whose effect on the target cell
is mediated by signal transduction pathways. Such pathways relay, amplify and integrate signals to elicit appropriate biological
responses. Protein kinases form crucial intermediate components of numerous signalling pathways. One group of protein kinases,
the mitogen-activated protein kinases (MAP kinases) are kinases involved in signalling pathways that respond primarily to
mitogens and stress stimuli. In vitro studies revealed that the MAP kinases are implicated in several cellular processes,
including cell division, differentiation, cell survival/apoptosis, gene expression, motility and metabolism. As such, dysfunction
of specific MAP kinases is associated with diseases such as cancer and immunological disorders. However, the genuine in vivo
functions of many MAP kinases remain elusive. Genetically modified mouse models deficient in a specific MAP kinase or expressing
a constitutive active or a dominant negative variant of a particular MAP kinase offer valuable tools for elucidating the biological
role of these protein kinases. In this review, we focus on the current status of MAP kinase knock-in and knock-out mouse models
and their phenotypes. Moreover, examples of the application of MAP kinase transgenic mice for validating therapeutic properties
of specific MAP kinase inhibitors, and for investigating the role of MAP kinase in pathogen-host interactions will be discussed. 相似文献
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Law WC Markowicz P Yong KT Roy I Baev A Patskovsky S Kabashin AV Ho HP Prasad PN 《Biosensors & bioelectronics》2007,23(5):627-632
In this study, a novel phase-sensitive surface plasmon resonance (SPR) setup, based on temporal modulation of a pumping beam by a photoelastic modulator, and subsequent extraction of phase information at the second and the third harmonics of the modulation frequency, has been developed to study biomolecular interactions on SPR-supporting gold. We demonstrated that the design setup provides ultra-high phase sensitivity, together with a wide dynamic range of measurements. In particular, the proposed scheme was used to study real-time interaction of biotin-protein and streptavidin-BSA complexes. We have found that the proposed technique has a detection limit as high as 2.89 x 10(-7) in terms of refractive index units (RIU). In terms of biosensing performance, a detection sensitivity of 1.3 nM from the streptavidin-maleimide/thiolated BSA complex binding reaction has also been demonstrated. 相似文献
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The fibrinogen gamma-module sequences, gamma190-202 or P1, and gamma377-395 or P2, were implicated in interaction with the alpha(M)I-domain of the leukocyte receptor alpha(M)beta(2). P1 is an integral part of the gamma-module central domain, while P2 is inserted into this domain forming an antiparallel beta-strand with P1. We hypothesized earlier that separation of P2 from P1 may regulate interaction of fibrin(ogen) with leukocytes during the inflammatory response. To test the relative contributions of these sequences to the interaction and the effect of their separation, we prepared the recombinant gamma-module (gamma148-411) and its halves, gamma148-286 and gamma287-411 fragments containing P1 and P2, respectively, and evaluated their affinities for the recombinant alpha(M)I-domain. In a solid-phase binding assay, the immobilized gamma-module exhibited high affinity for alpha(M)I (K(d) = 22 nM), while the affinities of the isolated gamma148-286 and gamma287-411 halves were much lower (K(d)'s = 521 and 194 nM, respectively), indicating that both halves contribute to the interaction in a synergistic manner. This is consistent with the above hypothesis. Further, we prepared the recombinant gamma148-191 and gamma192-286 fragments corresponding to the NH(2)-terminal and central domains, respectively, as well as gamma148-226 containing P1, and tested their interaction with alpha(M)I. The immobilized gamma192-286 fragment bound to alpha(M)I with K(d) = 559 nM, while both gamma148-191 and gamma148-226 failed to bind suggesting that P1 does not contribute substantially to the binding and that the binding occurs mainly through the gamma227-286 region. To further localize a putative binding sequence, we cleaved gamma192-286 and analyzed the resulting peptides. The only alpha(M)I-binding activity was associated with the gamma228-253 peptide, indicating that this region of the central domain contains a novel alpha(M)beta(2)-binding sequence. 相似文献
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Minchenko OH Opentanova IL Ogura T Minchenko DO Komisarenko SV Caro J Esumi H 《Acta biochimica Polonica》2005,52(4):881-888
Recently, we have shown that PFKFB4 gene which encodes the testis isoenzyme of PFKFB is also expressed in the prostate and hepatoma cancer cell lines. Here we have studied expression and hypoxic regulation of the testis isoenzyme of PFKFB4 in several malignant cell lines from a female organ--the mammary gland. Our studies clearly demonstrated that PFKFB4 mRNA is also expressed in mammary gland malignant cells (MCF-7 and T47D cell lines) in normoxic conditions and that hypoxia strongly induces it expression. To better understand the mechanism of hypoxic regulation of PFKFB4 gene expression, we used dimethyloxalylglycine, a specific inhibitor of HIF-1alpha hydroxylase enzymes, which strongly increases HIF-1alpha levels and mimics the effect of hypoxia. It was observed that PFKFB4 expression in the MCF7 and T47D cell lines was highly responsive to dimethyloxalylglycine, suggesting that the hypoxia responsiveness of PFKFB4 gene in these cell lines is regulated by HIF-1 proteins. Moreover, desferrioxamine and cobalt chloride, which mimic the effect of hypoxia by chelating or substituting for iron, had a similar stimulatory effect on the expression of PFKFB mRNA. In other mammary gland malignant cell lines (BT549, MDA-MB-468, and SKBR-3) hypoxia and hypoxia mimics also induced PFKFB4 mRNA, but to variable degrees. The hypoxic induction of PFKFB4 mRNA was equivalent to the expression of PFKFB3, Glut1, and VEGF, which are known HIF-1-dependent genes. Hypoxia and dimethyloxalylglycine increased the PFKFB4 protein levels in all cell lines studied except MDA-MB-468. Through site-specific mutagenesis in the 5'-flanking region of PFKFB4 gene the hypoxia response could be limited. Thus, this study provides evidence that PFKFB4 gene is also expressed in mammary gland cancer cells and strongly responds to hypoxia via an HIF-1alpha dependent mechanism. Moreover, the PFKFB4 and PFKFB3 gene expression in mammary gland cancer cells has also a significant role in the Warburg effect which is found in all malignant cells. 相似文献
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Lorkovic ZJ Lopato S Pexa M Lehner R Barta A 《The Journal of biological chemistry》2004,279(32):33890-33898
Ser/Arg (SR)-rich proteins are important splicing factors in both general and alternative splicing. By binding to specific sequences on pre-mRNA and interacting with other splicing factors via their RS domain they mediate different intraspliceosomal contacts, thereby helping in splice site selection and spliceosome assembly. While characterizing new members of this protein family in Arabidopsis, we have identified two proteins, termed CypRS64 and CypRS92, consisting of an N-terminal peptidyl-prolyl cis/trans isomerase domain and a C-terminal domain with many SR/SP dipeptides. Cyclophilins possess a peptidyl-prolyl cis/trans isomerase activity and are implicated in protein folding, assembly, and transport. CypRS64 interacts in vivo and in vitro with a subset of Arabidopsis SR proteins, including SRp30 and SRp34/SR1, two homologs of mammalian SF2/ASF, known to be important for 5' splice site recognition. In addition, both cyclophilins interact with U1-70K and U11-35K, which in turn are binding partners of SRp34/SR1. CypRS64 is a nucleoplasmic protein, but in most cells expressing CypRS64-GFP fusion it was also found in one to six round nuclear bodies. However, co-expression of CypRS64 with its binding partners resulted in re-localization of CypRS64 from the nuclear bodies to nuclear speckles, indicating functional interactions. These findings together with the observation that binding of SRp34/SR1 to CypRS64 is phosphorylation-dependent indicate an involvement of CypRS64 in nuclear pre-mRNA splicing, possibly by regulating phosphorylation/dephosphorylation of SR proteins and other spliceosomal components. Alternatively, binding of CypRS64 to proteins important for 5' splice site recognition suggests its involvement in the dynamics of spliceosome assembly. 相似文献