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1.
Following a TRAIL: Update on a ligand and its five receptors   总被引:28,自引:0,他引:28  
Identification of tumour necrosis factor apoptosis inducing ligand (TRAIL), a TNF family ligand, sparked a torrent of research, following an initial observation that it could kill tumour cells, but spare normal cells. Almost a decade after its discovery, and with five known receptors, the true physiological role of TRAIL is still debated and its anti-tumorigenic properties limited by potential toxicity. This review takes a comprehensive look at the story of this enigmatic ligand,addressing its remaining potential as a therapeutic and providing an overview of the TRAIL receptors themselves.  相似文献   

2.
New offspring due to sexual reproduction is not an instantaneous process from its birth,it takes time to be sexually mature.On the other hand,harvesting of commercially profitable fish population before the perfect size or weight is reached is not only a commercial loss but also risks the extinction of the population.Now,we discuss the issue of Ganges-Brahmaputra-Meghna basin,northern Bay of Bengal for the age-selective harvesting of Hilsa shad(Tenualosa ilisha)which lays eggs after its sexual maturation.Harvesting of hilsa before its sexual maturation risks its extinction and due to lamer body weight,it is not a commercially profitable policy.This is a reality of Sundarban estuary for hilsa fish harvesting,therefore,biologically and economically both India and Bangladesh are facing several problems.Empirical data of Frasergunje Fishing Harbor shows a clear picture as the supporting document of this mathematical problem.  相似文献   

3.
Zhang YW  Xu H 《Cell research》2007,17(5):385-386
The receptor tyrosine kinases (RTKs) are a family of cell surface proteins with diverse functions in proliferation, differentiation or cell-cell communication. When a specific ligand binds to its cognate receptor, a conformational change of this receptor due to the ligand-receptor interaction will lead to activation of the intrinsic tyrosine kinase residing in the intracellular domain of the receptor. The activation of this tyrosine kinase is essential for transducing the signals to a cascade of its downstream molecules that eventually cause related physiological responses .  相似文献   

4.
草原蝗虫的栖境选择   总被引:2,自引:0,他引:2  
颜忠诚  陈永林 《动物学报》1997,43(1):110-111
Habital selection is the behavioural chiice of a type of space where the animals prefer to live. It is obviousthat all animals are found in a more or less restricted range of suitable environment. The way in which animalpopulation selects a habitat may have important effects on obtaining food or mating, its vulnerability to preda-tors, its exposure to climatic stress,and so on. Different habitat selection is one of the principal relationshipswhich permit a species to exist, and it is one of the very important behaviour and ecological characteristics of  相似文献   

5.
The receptor tyrosine kinases (RTKs) are a family of cellsurface proteins with diverse functions in proliferation, dif-ferentiation or cell-cell communication. When a specific li-gand binds to its cognate receptor, a conformational changeof this receptor due to the ligand-receptor interaction willlead to activation of the intrinsic tyrosine kinase residing inthe intracellular domain of the receptor. The activation ofthis tyrosine kinase is essential for transducing the signals toa cascade of its downstream molecules that eventually causerelated physiological responses [1]. For example, binding ofnerve growth factor (NGF) to its receptor TrkA is essentialfor the proper development, patterning, and maintenanceof the mammalian nervous system. This ligand and recep-tor interaction will lead to the formation of a crab-shapedhomodimeric TrkA structure [2], and the subsequent activa-tion of its intrinsic RTK will cause auto-phosphorylationof its own intracellular tyrosine residues. PhosphorylatedTrkA receptors recruit and increase the phosphorylationof PLC-γ and Shc, which leads to activation of either thePI3K/Akt pathway or Ras/raf/ERK pathway. In the brainOf Alzheimer's disease (AD) patients, alterations of nervegrowth factor (NGF) and its receptor TrkA have beenreported to associate with AD pathogenesis [3]. However,the underlying mechanisms remain elusive.  相似文献   

6.
Leucine-rich repeat receptor-like kinases (LRR-RLKs) belong to a large group of cell surface proteins involved in many aspects of plant development and environmental responses in both monocots and dicots. Brassinosteroid insensitive 1 (BRI1), a member of the LRR X subfamily, was first identified through several forward genetic screenings for mutants insensitive to brassinosteroids (BRs), which are a class of plant-specific steroid hormones. Since its identification, BRI1 and its homologs had been proved as receptors perceiving BRs and initiating BR signaling. The co-receptor BRIl-associated kinase 1 and its homologs, and other BRI1 interacting proteins such as its inhibitor BRI1 kinase inhibitor I (BKI1) were identified by genetic andbiochemical approaches. The detailed mechanisms of BR perception by BRI1 and the activation of BRI1 receptor complex have also been elucidated. Moreover, several mechanisms for termination of the activated BRI1 signaling were also discovered. In this review, we will focus on the recent advances on the mechanism of BRI1 phosphorylation and activation, the regulation of its receptor complex, the structure basis of BRI1 ectodomain and BR recognition, its direct substrates, and the termination of the activated BRI1 receptor complex.  相似文献   

7.
The hippocampus is a brain region associated with memory, learning and spatial navigation, its aging-related dysfunction is a common sign of Alzheimer’s disease. Pig is a good model for human neurodegenerative disease, but our understanding of the regulatory program of the pig hippocampus and its cross-species conservation in humans remains limited. Here, we profiled chromatin accessibility in 33,409 high-quality nuclei and gene expression in 8,122 high-quality nuclei of the pig hippocampus at f...  相似文献   

8.
RNA editing for the mitochondrlal ATP9 gene of encoding regions has been observed in both cytoplasmic malesterile and maintainer lines of stem mustard, where its editing capacity varied spatially and temporally in the cytoplasmic male sterility (CMS) line. There were four RNA editing sites for the mitochondrial ATP9 gene according to Its normal editing sites in mustard, of which three sites occurred as C-to-U changes and one as a U-to-C change. As a result, the hydrophobicity of deduced ATP9 protein was reduced due to the conversions at its 17th, 45th and 64th positions. Meanwhile, the conservation of deduced ATP9 protein was enhanced by changes at the 56th position. Loss of a specific editing site for ATP9 was observed in juvenile roots, senile roots, senile leaves and floret buds of the CMS line. Comparatively, complete RNA editing for ATP9 gene was retained in juvenile roots, juvenile leaves and floret buds of its maintainer line; however, the loss of a specific editing site for ATP9 gene occurred at senile roots and senile leaves in its maintainer line. These observations allow us to produce a hypothesis that the dysfunction of a specific mitochondrial gene arising from RNA editing could probably be a factor triggering CMS and organ senescence through unknown cross-talk pathways during development.  相似文献   

9.
The genetic diversity of Varroa destructor (Anderson &Trueman)is limited outside its natural range due to population bottlenecks and its propensity to inbreed.In light of the arms race between V.destructor and its honeybee (Apis mellifera L.)host, any mechanism enhancing population admixture of the mite may be favored.One way that admixture can occur is when two genetically dissimilar mites coinvade a brood cell, with the progeny of the foundresses admixing.We determined the relatedness of 393 pairs of V.destructor foundresses,each pair collected from a single bee brood cell (n =five colonies).We used six microsatellites to identify the genotypes of mites coinvading a cell and calculated the frequency of pairs with different or the same genotypes.We found no deviation from random coinvasion,but the frequency of cells infested by mites with different genotypes was high.This rate of recombination,coupled with a high transmission rate of mites,homogenized the allelic pool of mites within the apiary.  相似文献   

10.
Structure and function of the NS1 protein of influenza A virus   总被引:3,自引:0,他引:3  
The avian influenza A virus currently prevailing in Asia causes fatal pneumonia and multipleorgan failure in birds and humans.Despite intensive research,understanding of the characteristics of influenzaA virus that determine its virulence is incomplete.NS1A protein,a non-structural protein of influenza Avirus,was reported to contribute to its pathogenicity and virulence.NS1A protein is a multifunctionalprotein that plays a significant role in resisting the host antiviral response during the influenza infection.Thisreview briefly outlines the current knowledge on the structure and function of the NS1A protein.  相似文献   

11.
12.
The new cytoplasmic male sterile (CMS) line Yewei A and its maintainer line Yewei B, with better agronomic characteristics, have been developed from a mutant of V20B (a rice maintainer line) through transformation of genomic DNA of wild rice (Oryza minuta J. S. Presl. ex C. B. Presl.). Analysis of molecular markers, DNA sequences, and Southern blot revealed that high DNA polymorphism exists between the mutant and its receptor, indicating that the special DNA fragment from O. minuta may be integrated into the genome of Yewei B. Therefore, transformation of genomic DNA from distant relatives to the plant of a target receptor may open an avenue for creating a new rice germplasm.  相似文献   

13.
甘肃鼢鼠粪尿气味对侵占行为的影响   总被引:5,自引:0,他引:5  
The Gansu zokor ( Myospalax cansus) is a solitary fossorial rodent, which inhabits its own tunnel system. The Gansu zokor are highly aggressive, and encounters between of two animals may end in the death or injury of one of them. In order to investigate the effect of fecaluria odor of the Gansu zokor on its invading behaviour, the behavioral methods were used to determine whether Gansu zokors use faeces to mark their own territorial boundaries and the effect on its excavation pattern. The results showed that when an intruder was introduced, the test animal almost always shifted its latrine location to the intruder‘s side. The Gansu zokor can detect the conspecific odor. In nonbreeding season, the odor of urine and faeces of Gansu zokors prolongs excavation of homosexual intruders and play a role in delaying conspecifics from entering the territory .  相似文献   

14.
<正> The problem of flapping motion control of Micro Air Vehicles (MAVs) with flapping wings was studied in this paper.Based upon the knowledge of skeletal and muscular components of hummingbird, a dynamic model for flapping wing wasdeveloped.A control scheme inspired by human memory and learning concept was constructed for wing motion control ofMAVs.The salient feature of the proposed control lies in its capabilities to improve the control performance by learning fromexperience and observation on its current and past behaviors, without the need for system dynamic information.Furthermore,the overall control scheme has a fairly simple structure and demands little online computations, making it attractive for real-timeimplementation on MAVs.Both theoretical analysis and computer simulation confirms its effectiveness.  相似文献   

15.
正The chloroplast is one of the most important organs in plants because of its essential role in photosynthesis.Studies have shown that the chloroplast was once a free-living cyanobacteria and was integrated into the host species through endosymbiosis(Goksoyr.1967).after which a large number of its genes had been donated to the host nuclear genome(Heins and  相似文献   

16.
Melatonin: A master regulator of plant development and stress responses   总被引:4,自引:0,他引:4  
Melatonin is a pleiotropic molecule with multiple functions in plants. Since the discovery of melatonin in plants, numerous studies have provided insight into the biosynthesis, catabolism, and physiological and biochemical functions of this important molecule. Here, we describe the biosynthesis of melatonin from tryptophan, as well as its various degradation pathways in plants. The identification of a putative melatonin receptor in plants has led to the hypothesis that melatonin is a hormone involved in regulating plant growth,aerial organ development, root morphology, and the floral transition. The universal antioxidant activity of melatonin and its role in preserving chlorophyll might explain its anti-senescence capacity in aging leaves. An impressive amount of research has focused on the role of melatonin in modulating postharvest fruit ripening by regulating the expression of ethylene-related genes.Recent evidence also indicated that melatonin functions in the plant's response to biotic stress,cooperating with other phytohormones and wellknown molecules such as reactive oxygen species and nitric oxide. Finally, great progress has been made towards understanding how melatonin alleviates the effects of various abiotic stresses, including salt, drought, extreme temperature, and heavy metal stress. Given its diverse roles, we propose that melatonin is a master regulator in plants.  相似文献   

17.
Function and regulation of Aurora/Ipllp kinase family in cell division   总被引:2,自引:0,他引:2  
Ke YW  Dou Z  Zhang J  Yao XB 《Cell research》2003,13(2):69-81
During mitosis,the parent cell distributes its genetic materials equally into two daughter cells through chromosome segregation,a complex movements orchestrated by mitotic kinases and its effector proteins.Faithful chromosome segregation and cytokinesis ensure that each daughter cell receives a full copy of genetic materials of parent cell.Defects in these processes can lead to aneuploidy or polyploidy.Aurora/Ipllp family, a class of conserved serine/threonine kinases,plays key roles in chromosome segregation and cytokinesis.This article highlights the function and regulation of Aurora/Ipllp family in mitosis and provides potential links between aberrant regulation of Aurora/Ipllp kinases and pathogenesis of human cancer.  相似文献   

18.
We present a bio-inspired strategy for designing embedded strain sensors in space structures. In insects, the campaniform sensillum is a hole extending through the cuticle arranged such that its shape changes in response to loads. The shape change is rotated through 90° by the suspension of a bell-shaped cap whose deflection is detected by a cell beneath the cuticle. It can be sensitive to displacements of the order of 1 nm. The essential morphology, a hole formed in a plate of fibrous composite mate- rial, was modelled by Skordos et al. who showed that global deformation of the plate (which can be flat, curved or a tube) induces higher local deformation of the hole due to its locally higher compliance. Further developments reported here show that this approach can be applied to groups of holes relative to their orientation. , The morphology of the sensillum in insects suggests that greater sensitivity can be achieved by arranging several holes in a regular pattern; that if the hole is oval it can be "aimed" to sense specific strain directions; and that either by controlling the shape of the hole or its relationship with other holes it can have a tuned response to dynamic strains. We investigate space applications in which novel bio-inspired strain sensors could successfully be used.  相似文献   

19.
Morphological Measurement and Analysis of Gymnarchus Niloticus   总被引:5,自引:0,他引:5  
Gymnarchus niloticus swims by undulations of a long-based dorsal fin, while its body axis is in many cases held straight during swimming. This paper provides a brief relevant introduction to Gymnarchus niloticus , which belongs to the African freshwater electric eels but can inspire our bionic interests in propulsion besides its abilities in electric sensing. A special larva of Gymnarchus niloticus was morphologically measured by photographing it with a piece of scale-calibrated paper as the background. Then we analyzed the data by a CFD-aided approach. Detailed flow patterns around the larva and a NACA0012 hydrofoil were respectively calculated and visualized at the Reynolds number of 7350 or so. The results show that the profile of Gymnarchus niloticus is well streamlined.  相似文献   

20.
The Darwin plant, also known as the Venus flytrap, Dionaea muscipula, has fascinated people since Darwin's time. The plant lives in nutrient-poor habitats but has been able to overcome the limitations of its surroundings by evolving a carnivorous lifestyle, particularly by modifying its leaves into active traps to catch animals. When flies, ants, or other small animals touch mechano-sensitive hairs protruding from the inner surface of the bi-lobed trap, it shuts within a fraction of a second.  相似文献   

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