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141.
Guillaume Jacquemet David M. Green Rebecca E. Bridgewater Alexander von Kriegsheim Martin J. Humphries Jim C. Norman Patrick T. Caswell 《The Journal of cell biology》2013,202(6):917-935
Inhibition of αvβ3 or expression of mutant p53 promotes invasion into fibronectin (FN)-containing extracellular matrix (ECM) by enhancing Rab-coupling protein (RCP)–dependent recycling of α5β1 integrin. RCP and α5β1 cooperatively recruit receptor tyrosine kinases, including EGFR1, to regulate their trafficking and downstream signaling via protein kinase B (PKB)/Akt, which, in turn, promotes invasive migration. In this paper, we identify a novel PKB/Akt substrate, RacGAP1, which is phosphorylated as a consequence of RCP-dependent α5β1 trafficking. Phosphorylation of RacGAP1 promotes its recruitment to IQGAP1 at the tips of invasive pseudopods, and RacGAP1 then locally suppresses the activity of the cytoskeletal regulator Rac and promotes the activity of RhoA in this subcellular region. This Rac to RhoA switch promotes the extension of pseudopodial processes and invasive migration into FN-containing matrices, in a RhoA-dependent manner. Thus, the localized endocytic trafficking of α5β1 within the tips of invasive pseudopods elicits signals that promote the reorganization of the actin cytoskeleton, protrusion, and invasion into FN-rich ECM. 相似文献
142.
143.
Alex Madrahimov Tomáš Helikar Bryan Kowal Guoqing Lu Jim Rogers 《Bulletin of mathematical biology》2013,75(6):988-1011
The replication and life cycle of the influenza virus is governed by an intricate network of intracellular regulatory events during infection, including interactions with an even more complex system of biochemical interactions of the host cell. Computational modeling and systems biology have been successfully employed to further the understanding of various biological systems, however, computational studies of the complexity of intracellular interactions during influenza infection is lacking. In this work, we present the first large-scale dynamical model of the infection and replication cycle of influenza, as well as some of its interactions with the host’s signaling machinery. Specifically, we focus on and visualize the dynamics of the internalization and endocytosis of the virus, replication and translation of its genomic components, as well as the assembly of progeny virions. Simulations and analyses of the models dynamics qualitatively reproduced numerous biological phenomena discovered in the laboratory. Finally, comparisons of the dynamics of existing and proposed drugs, our results suggest that a drug targeting PB1:PA would be more efficient than existing Amantadin/Rimantaine or Zanamivir/Oseltamivir. 相似文献
144.
Colin Butter Karen Staines Andrew van Hateren T. Fred Davison Jim Kaufman 《Immunogenetics》2013,65(8):609-618
In contrast to typical mammals, the chicken MHC (the BF-BL region of the B locus) has strong genetic associations with resistance and susceptibility to infectious pathogens as well as responses to vaccines. We have shown that the chicken MHC encodes a single dominantly expressed class I molecule whose peptide-binding motifs can determine resistance to viral pathogens, such as Rous sarcoma virus and Marek’s disease virus. In this report, we examine the response to a molecular defined vaccine, fp-IBD1, which consists of a fowlpox virus vector carrying the VP2 gene of infectious bursal disease virus (IBDV) fused with β-galactosidase. We vaccinated parental lines and two backcross families with fp-IBD1, challenged with the virulent IBDV strain F52/70, and measured damage to the bursa. We found that the MHC haplotype B15 from line 15I confers no protection, whereas B2 from line 61 and B12 from line C determine protection, although another locus from line 61 was also important. Using our peptide motifs, we found that many more peptides from VP2 were predicted to bind to the dominantly expressed class I molecule BF2*1201 than BF2*1501. Moreover, most of the peptides predicted to bind BF2*1201 did in fact bind, while none bound BF2*1501. Using peptide vaccination, we identified one B12 peptide that conferred protection to challenge, as assessed by bursal damage and viremia. Thus, we show the strong genetic association of the chicken MHC to a T cell vaccine can be explained by peptide presentation by the single dominantly expressed class I molecule. 相似文献
145.
In this study a new species of Neralsia is described, N. incompleta n. sp. The radial cell shape allows to distinguish it clearly from the rest of species of the genus. The distribution of Neralsia incompleta n. sp. is probably the entire American continent, having been collected from Canada to Paraguay. In spite of its abundance, the associated biology is unknown, although it should be related with parasitism of Diptera Cyclorrhapha. 相似文献
146.
Molly Sharlach Douglas Dahlbeck Lily Liu Joshua Chiu José M. Jiménez-Gómez Seisuke Kimura Daniel Koenig Julin N. Maloof Neelima Sinha Gerald V. Minsavage Jeffrey B. Jones Robert E. Stall Brian J. Staskawicz 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2013,126(3):601-609
The RXopJ4 resistance locus from the wild accession Solanum pennellii (Sp) LA716 confers resistance to bacterial spot disease of tomato (S. lycopersicum, Sl) caused by Xanthomonas perforans (Xp). RXopJ4 resistance depends on recognition of the pathogen type III effector protein XopJ4. We used a collection of Sp introgression lines (ILs) to narrow the RXopJ4 locus to a 4.2-Mb segment on the long arm of chromosome 6, encompassed by the ILs 6-2 and 6-2-2. We then adapted or developed a collection of 14 molecular markers to map on a segregating F2 population from a cross between the susceptible parent Sl FL8000 and the resistant parent RXopJ4 8000 OC7. In the F2 population, a 190-kb segment between the markers J350 and J352 cosegregated with resistance. This fine mapping will enable both the identification of candidate genes and the detection of resistant plants using cosegregating markers. The RXopJ4 resistance gene(s), in combination with other recently characterized genes and a quantitative trait locus (QTL) for bacterial spot disease resistance, will likely be an effective tool for the development of durable resistance in cultivated tomato. 相似文献
147.
Natalia Jiménez José Antonio Curiel Inés Reverón Blanca de las Rivas Rosario Mu?oz 《Applied and environmental microbiology》2013,79(14):4253-4263
Lactobacillus plantarum is a lactic acid bacterium able to degrade tannins by the subsequent action of tannase and gallate decarboxylase enzymes. The gene encoding tannase had previously been identified, whereas the gene encoding gallate decarboxylase is unknown. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of gallic-acid induced L. plantarum extracts showed a 54-kDa protein which was absent in the uninduced cells. This protein was identified as Lp_2945, putatively annotated UbiD. Homology searches identified ubiD-like genes located within three-gene operons which encoded the three subunits of nonoxidative aromatic acid decarboxylases. L. plantarum is the only bacterium in which the lpdC (lp_2945) gene and the lpdB and lpdD (lp_0271 and lp_0272) genes are separated in the chromosome. Combination of extracts from recombinant Escherichia coli cells expressing the lpdB, lpdC, and lpdC genes demonstrated that LpdC is the only protein required to yield gallate decarboxylase activity. However, the disruption of these genes in L. plantarum revealed that the lpdB and lpdC gene products are essential for gallate decarboxylase activity. Similar to L. plantarum tannase, which exhibited activity only in esters derived from gallic and protocatechuic acids, purified His6-LpdC protein from E. coli showed decarboxylase activity against gallic and protocatechuic acids. In contrast to the tannase activity, gallate decarboxylase activity is widely present among lactic acid bacteria. This study constitutes the first genetic characterization of a gallate decarboxylase enzyme and provides new insights into the role of the different subunits of bacterial nonoxidative aromatic acid decarboxylases. 相似文献
148.
Alejandro González Medina Lucas González Herrera M. Alejandra Perotti Gilberto Jiménez Ríos 《Experimental & applied acarology》2013,59(3):297-305
Despite the fact that mites were used at the dawn of forensic entomology to elucidate the postmortem interval, their use in current cases remains quite low for procedural reasons such as inadequate taxonomic knowledge. A special interest is focused on the phoretic stages of some mite species, because the phoront-host specificity allows us to deduce in many occasions the presence of the carrier (usually Diptera or Coleoptera) although it has not been seen in the sampling performed in situ or in the autopsy room. In this article, we describe two cases where Poecilochirus austroasiaticus Vitzthum (Acari: Parasitidae) was sampled in the autopsy room. In the first case, we could sample the host, Thanatophilus ruficornis (Küster) (Coleoptera: Silphidae), which was still carrying phoretic stages of the mite on the body. That attachment allowed, by observing starvation/feeding periods as a function of the digestive tract filling, the establishment of chronological cycles of phoretic behavior, showing maximum peaks of phoronts during arrival and departure from the corpse and the lowest values in the phase of host feeding. From the sarcosaprophagous fauna, we were able to determine in this case a minimum postmortem interval of 10 days. In the second case, we found no Silphidae at the place where the corpse was found or at the autopsy, but a postmortem interval of 13 days could be established by the high specificity of this interspecific relationship and the departure from the corpse of this family of Coleoptera. 相似文献
149.
Lepanthes variabilis, a new species from Costa Rica, is described and illustrated. It is endemic to the northern part of the Talamanca mountain range, from 2750–2850 m. It is compared to the similar L. minutilabia, which also occurs in Costa Rica. 相似文献
150.
Rubén Limiñana Martín Surroca Stephan Miralles Vicente Urios Juan Jiménez 《Bird Study》2013,60(2):126-131
Capsule Reproductive output in a natural habitat was higher than in birds breeding in cereal crops, highlighting the importance of natural habitats for the species. Aims To evaluate breeding in a natural habitat in inland Castellon province, Spain, and compare breeding parameters with other European populations. Methods Breeding population size in inland Castellon was recorded between 1981 and 2003. A logistic growth model was used to describe population increase. We also calculated clutch size, brood size, productivity, percentage of successful nests and fledging success for the period 1989–2003. Results Population size increased from three pairs in 1981 to 98 pairs in 2003. During 1989–2003, productivity (2.74 ± 1.49 fledglings/pair) and percentage of successful nests (84.%) were higher than observed in other European populations. Conclusions Our results show the importance of our study area for the conservation of this species in the Iberian Peninsula, as it might act as a source of colonists for other areas. Food and protection against predators might explain the high breeding output, which may in turn explain the rapid population growth in the area. The study also suggests that natural habitats might be important for the species elsewhere. 相似文献