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141.
Identification and characterization of a new oncogene derived from the regulatory subunit of phosphoinositide 3-kinase. 总被引:9,自引:1,他引:8
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C Jimenez D R Jones P Rodríguez-Viciana A Gonzalez-García E Leonardo S Wennstr?m C von Kobbe J L Toran L R-Borlado V Calvo S G Copin J P Albar M L Gaspar E Diez M A Marcos J Downward C Martinez-A I Mérida A C Carrera 《The EMBO journal》1998,17(3):743-753
p85/p110 phosphoinositide 3-kinase (PI3K) is a heterodimer composed of a p85-regulatory and a p110-catalytic subunit, which is involved in a variety of cellular responses including cytoskeletal organization, cell survival and proliferation. We describe here the cloning and characterization of p65-PI3K, a mutant of the regulatory subunit of PI3K, which includes the initial 571 residues of the wild type p85alpha-protein linked to a region conserved in the eph tyrosine kinase receptor family. We demonstrate that this mutation, obtained from a transformed cell, unlike previously engineered mutations of the regulatory subunit, induces the constitutive activation of PI3K and contributes to cellular transformation. This report links the PI3K enzyme to mammalian tumor development for the first time. 相似文献
142.
Alicia Toon Marcos Pérez‐Losada Carrie E. Schweitzer Rodney M. Feldmann Michael Carlson Keith A. Crandall 《Journal of Biogeography》2010,37(12):2275-2290
Aim The sequential break‐up of Gondwana is thought to be a dominant process in the establishment of shared biota across landmasses of the Southern Hemisphere. Yet similar distributions are shared by taxa whose radiations clearly post‐date the Gondwanan break‐up. Thus, determining the contribution of vicariance versus dispersal to seemingly Gondwanan biota is complex. The southern freshwater crayfishes (family Parastacidae) are distributed on Australia and New Guinea, South America, Madagascar and New Zealand and are unlikely to have dispersed via oceans, owing to strict freshwater limitations. We test the hypotheses that the break‐up of Gondwana has led to (1) a predominately east–west (((Australia, New Zealand: 80 Ma) Madagascar: 160–121 Ma) South America: 165–140 Ma), or (2) a southern (((Australia, South America: 52–35 Ma) New Zealand: 80 Ma) Madagascar: 160–121 Ma) pattern for parastacid crayfish. Further, we examine the evidence for a complete drowning of New Zealand and subsequent colonization by freshwater crayfish. Location Southern Hemisphere. Methods The evolutionary relationships among the 15 genera of Parastacidae were reconstructed using mitochondrial [16S, cytochrome c oxidase subunit I (COI)] and nuclear (18S, 28S) sequence data and maximum likelihood and Bayesian methods of phylogenetic reconstruction. A Bayesian (multidivtime ) molecular dating method using six fossil calibrations and phylogenetic inference was used to estimate divergence time among crayfish clades on Gondwanan landmasses. Results The South American crayfish are monophyletic and a sister group to all other southern crayfish. Australian crayfish are not monophyletic, with two Tasmanian genera, Spinastacoides and Ombrastacoides, forming a clade with New Zealand and Malagasy crayfish (both monophyletic). Divergence of crayfish among southern landmasses is estimated to have occurred around the Late Jurassic to Early Cretaceous (109–178 Ma). Main conclusions The estimated phylogenetic relationships and time of divergence among the Southern Hemisphere crayfishes were consistent with an east–west pattern of Gondwanan divergence. The divergence between Australia and New Zealand (109–160 Ma) pre‐dated the rifting at around 80 Ma, suggesting that these lineages were established prior to the break‐up. Owing to the age of the New Zealand crayfish, we reject the hypothesis that there was a complete drowning of New Zealand crayfish habitat. 相似文献
143.
Phinyarat Kongprakhon Alfonso Cuesta‐Marcos Patrick M. Hayes Vipa Hongtrakul Pattama Sirithunya Theerayuth Toojinda Nitsri Sangduen 《Journal of Phytopathology》2010,158(2):125-131
Pyricularia grisea is the most destructive and cosmopolitan fungal pathogen of rice and it can also cause disease on other agriculturally important cereals. We determined the number, location and interaction of quantitative trait loci (QTL) associated with resistance to P. grisea isolates obtained from rice (THL142 and THL222) and barley (TH16 and THL80) grown in Thailand. The isolates showed a spectrum of virulence when used to inoculate a series of differentials. We used a reference blast resistance mapping population of rice (IR64 × Azucena). IR64 was highly resistant, and Azucena was highly susceptible, to all four isolates. The numbers of resistant vs. susceptible progeny suggest that the resistance of IR64 is determined by two or three genes with additive effects. The correlation coefficients for all pairwise comparisons of disease severity were high and highest between barley isolates and between rice isolates. Four QTL were detected, one on each of the following chromosomes 2, 8, 9 and 10. IR64 contributed resistance alleles at three of the QTL (chromosomes 2, 8 and 9). Azucena contributed the resistance allele at the QTL on chromosome 10 in response to inoculation with isolate THL142. The results of the QTL analysis support interpretation of the phenotypic frequency distributions regarding the number of genes determining resistance to the four isolates in this population. Our results are novel in adding blast isolates from barley to the catalogue of pathogen specificities to which a gene, or genes, from IR64 confer resistance. 相似文献
144.
Jens T. Høeg Yair Achituv Benny K.K. Chan Karen Chan Peter Gram Jensen Marcos Pérez‐Losada 《Journal of morphology》2009,270(2):241-255
We used scanning electron microscopy (SEM) to describe cypris morphology in species of the barnacles Ibla and Paralepas, both of which are pivotal in understanding cirripede evolution. In Ibla, we also studied late naupliar stages with video and SEM. Special emphasis was put on the lattice organs, the antennules and the thorax and telson. In Paralepas we had settled specimens only and could therefore only investigate the carapace with the lattice organs. Cyprids of Ibla quadrivalvis and Paralepas dannevigi have five sets of lattice organs, grouped as two anterior and three posterior pairs. The organs are of the pore‐field type and the terminal pore is situated anteriorly in the first pair, just as in the Rhizocephala and the Thoracica. In Ibla the armament of antennular sensilla resembles that found in the Thoracica but differs from the Rhizocephala. The absence of setules on the A and B setae sited terminally on the fourth antennular segment is a similarity with the Acrothoracica. The attachment disc is angled rather than facing distally and is encircled by a low cuticular velum. The thoracopods have two‐segmented endopods and exopods as in the Thoracica, but the number, shape, and position of thoracopodal setae differ somewhat from other species of that superorder. Both Ibla and Paralepas cyprids have a deeply cleaved telson, but no independent abdominal part. In cypris morphology, Ibla and Paralepas show several synapomorphies with the clade comprising Rhizocephala and Thoracica and there are no specific apomorphies with either the Acrothoracica, the Rhizocephala or any particular subgroup within the Thoracica. This is in agreement with recent molecular evidence that Ibla (Ibliformes) is the sister taxon to all other Thoracica and the ibliforms therefore become the outgroup of choice for studying character evolution within the superorder. Paralepas, and other pedunculated barnacles without shell plates, are apparently not primitive but are secondarily evolved and nested within the Thoracica. J. Morphol., 2009. © 2008 Wiley‐Liss, Inc. 相似文献
145.
Consuelo Latorre Fortes-Dias Roberta Márcia Marques dos Santos Angelo José Magro Marcos Roberto de Mattos Fontes Carlos Chávez-Olórtegui Claude Granier 《Biochimie》2009,91(11-12):1482-1492
Crotoxin (CA.CB) is a β-neurotoxin from Crotalus durissus terrificus snake venom that is responsible for main envenomation effects upon biting by this snake. It is a heterodimer of an acidic protein (CA) devoid of any biological activity per se and a basic, enzymatically active, PLA2 counterpart (CB). Both lethal and enzymatic activities of crotoxin have been shown to be inhibited by CNF, a protein from the blood of C. d. terrificus snakes. CNF replaces CA in the CA.CB complex, forming a stable, non-toxic complex CNF.CB. The molecular sites involved in the tight interfacial protein–protein interactions in these PLA2-based complexes have not been clearly determined. To help address this question, we used the peptide arrays approach to map possible interfacial interaction sites in CA.CB and CNF.CB. Amino acid stretches putatively involved in these interactions were firstly identified in the primary structure of CB. Further analysis of the interfacial availability of these stretches in the presumed biologically active structure of CB, suggested two interaction main sites, located at the amino-terminus and β-wing regions. Peptide segments at the carboxyl-terminus of CB were also suggested to play a secondary role in the binding of both CA and CNF. 相似文献
146.
147.
Alicja. J. Copik Aleksander Baldys Khanh Nguyen Sunil Sahdeo Hoangdung Ho Alan Kosaka Paul J. Dietrich Bill Fitch John R. Raymond Anthony P. D. W. Ford Donald Button Marcos E. Milla 《PloS one》2015,10(1)
The α1A-AR is thought to couple predominantly to the Gαq/PLC pathway and lead to phosphoinositide hydrolysis and calcium mobilization, although certain agonists acting at this receptor have been reported to trigger activation of arachidonic acid formation and MAPK pathways. For several G protein-coupled receptors (GPCRs) agonists can manifest a bias for activation of particular effector signaling output, i.e. not all agonists of a given GPCR generate responses through utilization of the same signaling cascade(s). Previous work with Gαq coupling-defective variants of α1A-AR, as well as a combination of Ca2+ channel blockers, uncovered cross-talk between α1A-AR and β2-AR that leads to potentiation of a Gαq-independent signaling cascade in response to α1A-AR activation. We hypothesized that molecules exist that act as biased agonists to selectively activate this pathway. In this report, isoproterenol (Iso), typically viewed as β-AR-selective agonist, was examined with respect to activation of α1A-AR. α1A-AR selective antagonists were used to specifically block Iso evoked signaling in different cellular backgrounds and confirm its action at α1A-AR. Iso induced signaling at α1A-AR was further interrogated by probing steps along the Gαq /PLC, Gαs and MAPK/ERK pathways. In HEK-293/EBNA cells transiently transduced with α1A-AR, and CHO_α1A-AR stable cells, Iso evoked low potency ERK activity as well as Ca2+ mobilization that could be blocked by α1A-AR selective antagonists. The kinetics of Iso induced Ca2+ transients differed from typical Gαq- mediated Ca2+ mobilization, lacking both the fast IP3R mediated response and the sustained phase of Ca2+ re-entry. Moreover, no inositol phosphate (IP) accumulation could be detected in either cell line after stimulation with Iso, but activation was accompanied by receptor internalization. Data are presented that indicate that Iso represents a novel type of α1A-AR partial agonist with signaling bias toward MAPK/ERK signaling cascade that is likely independent of coupling to Gαq. 相似文献
148.
Marcos R. Bornschein Carina R. Firkowski Diego Baldo Luiz F. Ribeiro Ricardo Belmonte-Lopes Leandro Corrêa Sérgio A. A. Morato Marcio R. Pie 《PloS one》2015,10(12)
Three new species of Melanophryniscus are described from the Serra do Mar mountain range of the state of Santa Catarina, southern Brazil. All species are found at intermediate to high altitudes and share phytotelm-breeding as their reproductive strategy. The new species are distinguished from other phytotelm-breeding Melanophryniscus based on different combinations of the following traits: snout-vent length, presence of white and/or yellow spots on forearms, mouth, belly and cloaca, pattern and arrangement of warts, and presence and number of corneous spines. The discovery of these species in a rather restricted geographical area suggests that the diversity of phytotelm-breeding species of Melanophryniscus might be severely underestimated. The conservation status of these species is of particular concern, given that one of them is at risk of extinction not only due to its restricted habitat, but also because of anthropogenic disturbances. 相似文献
149.
Zilca Campos Guilherme Mour?o Marcos Coutinho William E. Magnusson Balbina M. A. Soriano 《PloS one》2015,10(6)
We monitored the number of caiman (Caiman crocodilus yacare) nests in two ranches in the Brazilian Pantanal that cover an area of about 50.000 ha for 28 years (1987–2014). The number of nests was related to combinations of rainfall, water level, and number of days with temperature below 20°C, depending on the area. Most of the variation in number of nests could not be predicted by the environmental variables, but could be represented mathematically by a sine wave. We were not able to identify any external driver and suspect that the regular fluctuations may have resulted from an intrinsic population process. Presently, ranches are used as management units under the legislation for ranching Pantanal caimans. However, although some breeding females were recaptured in the area after periods of up to 21 years, most were not recaptured near nests or in general surveys of the area, suggesting that females are not strongly philopatric and that ranches do not represent isolated demographic units. 相似文献
150.
Maria Cristina Schneider Patricia Najera Martha M. Pereira Gustavo Machado Celso B. dos Anjos Rogério O. Rodrigues Gabriela M. Cavagni Claudia Mu?oz-Zanzi Luis G. Corbellini Mariana Leone Daniel F. Buss Sylvain Aldighieri Marcos A. Espinal 《PLoS neglected tropical diseases》2015,9(11)