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61.
McConville MJ Ilgoutz SC Teasdale RD Foth BJ Matthews A Mullin KA Gleeson PA 《European journal of cell biology》2002,81(9):485-495
The GRIP domain, found in a family of coiled-coil peripheral membrane Golgi proteins, is a specific targeting sequence for the trans-Golgi network of animal cells. In this study we show that a coiled-coil protein with a GRIP domain occurs in the primitive eukaryote, Trypanosoma brucei, and that reporter proteins containing this domain can be used as a marker for the poorly characterized trans Golgi/trans-Golgi network of trypanosomatid parasites. The T. brucei GRIP domain, when fused to the carboxyl terminus of the green fluorescent protein (GFP-TbGRIP), was efficiently localized to the Golgi apparatus of transfected COS cells. Overexpression of GFP-TbGRIP in COS cells displaced the endogenous GRIP protein, GCC1p, from the Golgi apparatus indicating that the trypanosomatid and mammalian GRIP sequences interact with similar membrane determinants. GFP fusion proteins containing either the T. brucei GRIP domain or the human p230 GRIP (p230GRIP) domain were also expressed in the trypanosomatid parasite, Leishmania mexicana, and localized by fluorescence and immuno-electron microscopy to the trans face of the single Golgi apparatus and a short tubule that extended from the Golgi apparatus. Binding of GFP-p230GRIP to Golgi membranes in L. mexicana was abrogated by mutation of a critical tyrosine residue in the p230 GRIP domain. The levels of GFP-GRIP fusion proteins were dramatically reduced in stationary-phase L. mexicana promastigotes, suggesting that specific Golgi trafficking steps may be down-regulated as the promastigotes cease dividing. This study provides a protein marker for the trans-Golgi network of trypanosomatid parasites and suggests that the GRIP domain binds to a membrane component that has been highly conserved in eukaryotic evolution. 相似文献
62.
MOTIVATION: Structured non-coding RNAs (ncRNAs) have a very important functional role in the cell. No distinctive general features common to all ncRNA have yet been discovered. This makes it difficult to design computational tools able to detect novel ncRNAs in the genomic sequence. RESULTS: We devised an algorithm able to detect conserved secondary structures in both pairwise and multiple DNA sequence alignments with computational time proportional to the square of the sequence length. We implemented the algorithm for the case of pairwise and three-way alignments and tested it on ncRNAs obtained from public databases. On the test sets, the pairwise algorithm has a specificity greater than 97% with a sensitivity varying from 22.26% for Blast alignments to 56.35% for structural alignments. The three-way algorithm behaves similarly. Our algorithm is able to efficiently detect a conserved secondary structure in multiple alignments. 相似文献
63.
Wilhelm V Huaracán B Martínez R Rosemblatt M Burzio LO Valenzuela PD 《Biological research》2003,36(3-4):421-428
The genes encoding the heat shock proteins HSP10 and HSP16 of the salmon pathogen Piscirickettsia salmonis have been isolated and sequenced. The HSP10 coding sequence is located in an open reading frame of 291 base pairs encoding 96 aminoacids. The HSP16 coding region was isolated as a 471 base pair fragment encoding a protein of 156 aminoacids. The deduced aminoacid sequences of both proteins show a significant homology to the respective protein from other prokaryotic organisms. Both proteins were expressed in E. coli as fusion proteins with thioredoxin and purified by chromatography on Nicolumn. A rabbit serum against P. salmonis total proteins reacts with the recombinant HSP10 and HSP16 proteins. Similar reactivity was determined by ELISA using serum from salmon infected with P. salmonis. The possibility of formulating a vaccine containing these two proteins is discussed. 相似文献
64.
65.
Minutolo F Bertini S Betti L Danesi R Gervasi G Giannaccini G Papi C Placanica G Barontini S Rapposelli S Macchia M 《Bioorganic & medicinal chemistry letters》2003,13(24):4405-4408
Phosphonoacetamido(oxy) groups have proven to be good mimics of the diphosphate portion in geranylgeranyl protein transferase I (GGTase I) inhibitors. The introduction of small alkyl groups (Me, Et) into the diphosphate mimic moiety caused a further decrease in collateral farnesyl protein transferase (FTase) inhibitory activity, thereby improving GGTase I over FTase selectivity. 相似文献
66.
Okubo S Bernardo NL Elliott GT Hess ML Kukreja RC 《American journal of physiology. Heart and circulatory physiology》2000,279(5):H2269-H2276
We investigated the role of tyrosine kinase (TK) signaling in the opening of the ATP-sensitive K(+) (K(ATP)) channel and 72-kDa heat shock protein (HSP72) expression during late preconditioning. Rabbits were subjected to surgical operation (sham) or were preconditioned (PC) with four cycles of 5 min of ischemia and 10 min of reperfusion. Twenty-four hours later, animals were subjected to 30 min of ischemia and 180 min of reperfusion. Genistein (1 mg/kg ip) was used to block the receptor TK. Six groups were studied: control, sham, genistein-sham, PC, genistein-PC, and vehicle-PC group (1% dimethyl sulfoxide). Genistein or vehicle was given 30 min before the surgical procedure. Genistein pretreatment decreased the expression of HSP72 in PC hearts and suppressed action potential duration shortening during ischemia in sham and PC groups. Infarct size (%risk area) was reduced in the PC (11.6 +/- 1.0%) and vehicle-PC (19.3 +/- 2.0%) compared with the control (40.0 +/- 3.8%) or sham (46.0 +/- 2.0%) groups (P < 0.05). Genistein pretreatment increased infarct size to 46.4 +/- 4.1% in the PC hearts. We conclude that TK signaling is involved in K(ATP) channel opening and HSP72 expression during late PC. 相似文献
67.
Calonje M Novaes-Ledieu M Bernardo D Ahrazem O García Mendoza C 《Canadian journal of microbiology》2000,46(2):101-109
The chemical structure of cell walls and fractions of Verticillium fungicola, a pathogen of Agaricus bisporus, as well as their corresponding ultrastructures were studied. There are at least three chemically distinct types of carbohydrate polymers: one yielding mannose with lower amounts of galactose and glucose (glucogalactomannan), another one composed mainly of glucose (glucan), and a third one containing only N-acetylglucosamine (chitin). Attempts were made to locate these materials in situ by comparing electron micrographs of shadowed and sectioned cell walls, and also by indirect immunofluorescence. It was shown that none of these polymers constituted a completely physically distinct layer, but there seem to be different solubility properties in the outer, inner, and intermediate layers. It was also shown that fibrillar material (chitin) embedded in cementing glucan constituted the residual inner fraction of the original wall material. Indirect immunofluorescence showed the location of a significant amount of glucogalactomannan on the surface of the walls in which rodlet structures were visualized by electron microscopy. 相似文献
68.
Previous studies have shown that exposure to altered magnetic fields alters analgesic responses in a variety of species, including humans. Here we examined whether deprivation of the normally occurring geomagnetic field also affects stress-induced analgesia, by measuring the nociceptive responses of C57 male mice that were restraint-stressed in a hypogeomagnetic environment (inside a mu-metal box). Stress-induced analgesia was significantly suppressed in a manner comparable to that observed in mice that were either exposed to altered oscillating magnetic fields or treated with the prototypic opiate antagonist naloxone. These results represent the first piece of evidence that a period in a hypogeomagnetic environment inhibits stress-induced analgesia. 相似文献
69.
Luis F. Callado J. Javier Meana Bernardo Grijalba Angel Pazos †Magdalena Sastre †Jesús A. García-Sevilla 《Journal of neurochemistry》1998,70(3):1114-1123
Abstract: The α2A- and α2C-adrenoceptor subtypes were evaluated in postmortem brains from suicides with depression (n = 22), suicides with other diagnoses (n = 12), and controls (n = 26). Membrane assays with the antagonist [3H]RX821002 (2-[3H]methoxyidazoxan) suggested the presence of α2A-adrenoceptors in the frontal cortex and both α2C-adrenoceptors and α2A-adrenoceptors in the caudate. The proportions in caudate were similar in controls (α2A, 86%; α2C, 14%), depressed suicides (α2A, 91%; α2C, 9%), and suicides with other diagnoses (α2A, 88%; α2C, 12%). Autoradiography of [3H]RX821002 binding under α2B/C-adrenoceptor-masking conditions confirmed the similar densities of α2A-adrenoceptors in the cortex, hippocampus, and striatum from controls and suicides. In the frontal cortex of depressed suicides, competition of [3H]RX821002 binding by (?)-adrenaline revealed a greater proportion (61 ± 9%) of α2A-adrenoceptors in the high-affinity conformation for agonists than in controls (39 ± 5%). Simultaneous analysis with the agonists [3H]clonidine and [3H]UK14304 and the antagonist [3H]RX821002 in the same depressed suicides confirmed the enhanced α2A-adrenoceptor density when evaluated by agonist, but not by antagonist, radioligands. The results indicate that depression is associated with a selective increase in the high-affinity conformation of the brain α2A-adrenoceptors. 相似文献
70.
One hundred and thirteen dogs of different breeds and with different clinical forms of external otitis were mycologically and bacteriologically examined. Forty six of those dogs showed abnormal cerumen with a high yeasts contamination. These yeasts belong to four species: Malassezia pachydermatis (80.4%), Cryptococcus laurentii (13.1%), Candida parapsilosis (4.3%) and Trichosporon cutaneum (2.1%). All strains, excepting C. laurentii were highly lipolytic. Most of the clinical cases associated with those yeasts were chronic, with hyperkeratosis and lichenification, and most of them were relapsed otitis (91.3%). The most affected dogs were a pendulous ears breeding (65.7%) and males (86.8%). Some dogs had other cutaneous disorders (seborrhoeic dermatitis, pemphigus). In vitro tests, using seven different antifungal drugs were systematically performed. All strains revealed to be 5-fluorocytosine-resistant and 32% of them were also resistant to nystatin. One M. pachydermatis isolated was resistant to all of the tested antifungal drugs. 相似文献