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11.
Pituitary adenylate cyclase activating peptide (PACAP) immunoreactivity in the ureter of the duck 总被引:2,自引:0,他引:2
Mirabella N Squillacioti C Germano G Varricchio E Paino G 《Cell and tissue research》2001,305(3):341-349
The presence, distribution and colocalisation of pituitary adenylate cyclase activating peptide (PACAP) immunoreactivity have been studied in the duck ureter by using Western blot analysis, radioimmunoassays (RIA) and immunohistochemistry. The presence of both PACAP-38 and PACAP-27 was demonstrated, PACAP-38 being the predominant form. PACAP-immunoreactive fibres and neurons were found in all the ureteral layers. Double immunostaining showed that PACAP was almost completely colocalised with vasoactive intestinal peptide (VIP). Moreover, PACAP was found in substance P (SP)-containing ureteral nerve fibres and in SP-containing dorsal root ganglion neurons. RIA performed on denervated ureters demonstrated that almost half of the ureteral PACAP was extrinsic in origin. These findings suggest that, in birds, PACAP has a role in diverse nerve-mediated ureteral functions. 相似文献
12.
The heterodimeric HU protein was isolated from Escherichia coli as one of the most abundant DNA binding proteins associated with the bacterial nucleoid. HUalphabeta is composed of two very homologous subunits, but HU can also be present in E. coli under its two homodimeric forms, HUalpha(2) and HUbeta(2). This protein is conserved either in its heterodimeric form or in one of its homodimeric forms in all bacteria, in plant chloroplasts and in some viruses. HU can participate, like the histones, in the maintenance of DNA supercoiling and in DNA condensation. This protein which does not recognize any specific sequence on double-stranded DNA, has been shown to bind specifically to cruciform DNA as does the eukaryotic HMG1 protein and to a series of structures which are found as intermediates of DNA repair, e.g., nick, gap, 3'overhang, etc. The strong binding of HU to these diverse DNA structures could explain, in part at least, its pleiotropic role in the bacterial cell. To understand all the facets of its interactions with nucleic acids, it was necessary to develop a procedure which allowed the purification of the three forms of HU under their native form and without the nuclease activity strongly associated with the protein. We describe here such a procedure as well as demonstrating that the three histidine-tagged HUs we have produced, have conserved the binding characteristics of native HUs. Interestingly, by two complementation tests, we show that the histidine-tagged HUs are fully active in vivo. 相似文献
13.
Elisabetta Panza Paola De Cicco Chiara Armogida Giosuè Scognamiglio Vincenzo Gigantino Gerardo Botti Domenico Germano Maria Napolitano Andreas Papapetropoulos Mariarosaria Bucci Giuseppe Cirino Angela Ianaro 《Pigment cell & melanoma research》2015,28(1):61-72
In humans, two main metabolic enzymes synthesize hydrogen sulfide (H2S): cystathionine γ lyase (CSE) and cystathionine β synthase (CBS). A third enzyme, 3‐mercaptopyruvate sulfurtransferase (3‐MST), synthesizes H2S in the presence of the substrate 3‐mercaptopyruvate (3‐MP). The immunohistochemistry analysis performed on human melanoma samples demonstrated that CSE expression was highest in primary tumors, decreased in the metastatic lesions and was almost silent in non‐lymph node metastases. The primary role played by CSE was confirmed by the finding that the overexpression of CSE induced spontaneous apoptosis of human melanoma cells. The same effect was achieved using different H2S donors, the most active of which was diallyl trisulfide (DATS). The main pro‐apoptotic mechanisms involved were suppression of nuclear factor‐κB activity and inhibition of AKT and extracellular signal‐regulated kinase pathways. A proof of concept was obtained in vivo using a murine melanoma model. In fact, either l ‐cysteine, the CSE substrate, or DATS inhibited tumor growth in mice. In conclusion, we have determined that the l ‐cysteine/CSE/H2S pathway is involved in melanoma progression. 相似文献
14.
The uptake of glutamate in nerve synapses is carried out by the excitatory amino acid transporters (EAATs), involving the cotransport of a proton and three Na+ ions and the countertransport of a K+ ion. In this study, we use an EAAT3 homology model to calculate the pKa of several titratable residues around the glutamate binding site to locate the proton carrier site involved in the translocation of the substrate. After identifying E374 as the main candidate for carrying the proton, we calculate the protonation state of this residue in different conformations of EAAT3 and with different ligands bound. We find that E374 is protonated in the fully bound state, but removing the Na2 ion and the substrate reduces the pKa of this residue and favors the release of the proton to solution. Removing the remaining Na+ ions again favors the protonation of E374 in both the outward- and inward-facing states, hence the proton is not released in the empty transporter. By calculating the pKa of E374 with a K+ ion bound in three possible sites, we show that binding of the K+ ion is necessary for the release of the proton in the inward-facing state. This suggests a mechanism in which a K+ ion replaces one of the ligands bound to the transporter, which may explain the faster transport rates of the EAATs compared to its archaeal homologs. 相似文献
15.
Cappelli A Valenti S Mancini A Giuliani G Anzini M Altieri S Bortolussi S Ferrari C Clerici AM Zonta C Carraro F Filippi I Giorgi G Donati A Ristori S Vomero S Concas A Biggio G 《Bioconjugate chemistry》2010,21(12):2213-2221
Potential boron neutron capture therapy (BNCT) agents have been designed on the basis of the evidence about translocator protein (TSPO) overexpression on the outer mitochondrial membrane of tumor cells. The structure of the first TSPO ligand bearing a carborane cage (compound 2d) has been modified in order to find a suitable candidate for in vivo studies. The designed compounds were synthesized and evaluated for their potential interaction with TSPO and tumor cells. In vitro biological evaluation showed in the case of fluoromethyl derivative 4b a nanomolar TSPO affinity very similar to that of 2d, a significantly lower cytotoxicity, and a slightly superior performance as boron carrier toward breast cancer cells. Moreover, compound 4b could be used as a 1?F magnetic resonance imaging (MRI) agent as well as labeled with 11C or 1?F to obtain positron emission tomography (PET) radiotracers in order to apply the "see and treat" strategy in BNCT. 相似文献
16.
Ferrari G Pastorelli R Buchi F Spinelli E Gozzini A Bosi A Santini V 《Journal of proteome research》2007,6(1):367-375
Imatinib is the first molecular targeted therapy that has shown clinical success, but imatinib acquired resistance, although a rare event, is critical during the therapy of chronic myelogenous leukaemia (CML). With the aim of better understanding the molecular mechanisms accompanying acquisition of resistance to this drug, a comparative proteomic approach was undertaken on CML cell lines LAMA 84 S (imatinib sensitive) and LAMA 84 R (imatinib resistant). Forty-four differentially expressed proteins were identified and categorized into five main functional classes: (I) heat shock proteins and chaperones; (II) nucleic acid interacting proteins (binding/synthesis/stability); (III) structural proteins, (IV) cell signaling, and (V) metabolic enzymes. Several heat shock proteins known to complex Bcr-Abl were overexpressed in imatinib resistant cells, showing a possible involvement of these proteins in the mechanism of resistance. HnRNPs also resulted in being up-regulated in imatinib resistant cells. These proteins have been shown to be strongly and directly related to Bcr-Abl activity. To our knowledge, this is the first direct proteomic comparison of imatinib sensitive/resistant CML cell lines. 相似文献
17.
Zakrzewski Martha Wilkins Sarah J. Helman Sheridan L. Brilli Elisa Tarantino Germano Anderson Gregory J. Frazer David M. 《Biometals》2022,35(1):27-38
BioMetals - Iron deficiency is one of the most common nutritional deficiencies worldwide and is often treated with oral iron supplements. However, commonly used supplements, including those based... 相似文献
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19.
Germano Siqueira Adriane MF Milagres Walter Carvalho Gerald Koch André Ferraz 《Biotechnology for biofuels》2011,4(1):7
Background
Lignin and hemicelluloses are the major components limiting enzyme infiltration into cell walls. Determination of the topochemical distribution of lignin and aromatics in sugar cane might provide important data on the recalcitrance of specific cells. We used cellular ultraviolet (UV) microspectrophotometry (UMSP) to topochemically detect lignin and hydroxycinnamic acids in individual fiber, vessel and parenchyma cell walls of untreated and chlorite-treated sugar cane. Internodes, presenting typical vascular bundles and sucrose-storing parenchyma cells, were divided into rind and pith fractions. 相似文献20.
Bonnet M Pardini M Meacci F Orrù G Yesilkaya H Jarosz T Andrew PW Barer M Checchi F Rinder H Orefici G Rüsch-Gerdes S Fattorini L Oggioni MR Melzer J Niemann S Varaine F 《PloS one》2011,6(8):e23081