排序方式: 共有169条查询结果,搜索用时 15 毫秒
91.
Jonassen T Marbois BN Faull KF Clarke CF Larsen PL 《The Journal of biological chemistry》2002,277(47):45020-45027
The Caenorhabditis elegans clk-1 mutants lack coenzyme Q(9) and instead accumulate the biosynthetic intermediate demethoxy-Q(9) (DMQ(9)). clk-1 animals grow to reproductive adults, albeit slowly, if supplied with Q(8)-containing Escherichia coli. However, if Q is withdrawn from the diet, clk-1 animals either arrest development as young larvae or become sterile adults depending upon the stage at the time of the withdrawal. To understand this stage-dependent response to a Q-less diet, the quinone content was determined during development of wild-type animals. The quinone content varies in the different developmental stages in wild-type fed Q(8)-replete E. coli. The amounts peak at the second larval stage, which coincides with the stage of arrest of clk-1 larvae fed a Q-less diet from hatching. Levels of the endogenously synthesized DMQ(9) are high in the clk-1(qm30)-arrested larvae and sterile adults fed Q-less food. Comparison of quinones from animals fed a Q-replete or a Q-less diet establishes that the Q(8) present is assimilated from the E. coli. Furthermore, this E. coli-specific Q(8) is present in mitochondria isolated from fertile clk-1(qm30) adults fed a Q-replete diet. These results suggest that the uptake and transport of dietary Q(8) to mitochondria prevent the arrest and sterility phenotypes of clk-1 mutants and that DMQ is not functionally equivalent to Q. 相似文献
92.
Diverse dengue type 2 virus populations contain recombinant and both parental viruses in a single mosquito host
下载免费PDF全文
![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Envelope (E) protein genes sampled from populations of dengue 2 (DEN-2) virus in individual Aedes aegypti mosquitoes and in serum from dengue patients were copied to cDNA, cloned, and sequenced. The nucleotide sequences of the E genes in more than 70% of the clones differed from the consensus sequence for the corresponding virus population at up to 11 sites, and 24 of the 94 clones contained at least one stop codon. Virus populations recovered up to 2 years apart yielded clones with similar polymorphisms in the E gene. For one mosquito, the clones obtained fell into two genotypes. One group of sequences was closely related to those of viruses recovered from dengue patients in the same locality (Yangon, Myanmar) since 1995 and were classified as Asian 1 genotype. The second group were Cosmopolitan genotype viruses which were also circulating in Yangon in 2000 and which were related to DEN-2 viruses sampled from southern China in 1999. Finally, one clone was identified as a recombinant genome composed of portions of these two "parental" genotypes. This is the first report of recombinant and parental dengue viruses in a single host. 相似文献
93.
Ca2+ signals in CD4+ T cells during early contacts with antigen-bearing dendritic cells in lymph node 总被引:2,自引:0,他引:2
Wei SH Safrina O Yu Y Garrod KR Cahalan MD Parker I 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(3):1586-1594
T cell activation by APC requires cytosolic Ca(2+) ([Ca(2+)](i)) elevation. Using two-photon microscopy, we visualized Ca(2+) signaling and motility of murine CD4(+) T cells within lymph node (LN) explants under control, inflammatory, and immunizing conditions. Without Ag under basal noninflammatory conditions, T cells showed infrequent Ca(2+) spikes associated with sustained slowing. Inflammation reduced velocities and Ca(2+) spiking in the absence of specific Ag. During early Ag encounter, most T cells engaged Ag-presenting dendritic cells in clusters, and showed increased Ca(2+) spike frequency and elevated basal [Ca(2+)](i). These Ca(2+) signals persisted for hours, irrespective of whether T cells were in contact with visualized dendritic cells. We propose that sustained increases in basal [Ca(2+)](i) and spiking frequency constitute a Ca(2+) signaling modality that, integrated over hours, distinguishes immunogenic from basal state in the native lymphoid environment. 相似文献
94.
Maha Faden Fatema AlZahrani Roberto Mendoza-Londono Lucie Dupuis Taila Hartley Peter Kannu Julian?A. Raiman Andrew Howard Wen Qin Martine Tetreault Joan?Qiongchao Xi Imadeddin Al-Thamer CareRare Canada Consortium Richard?L. Maas Kym Boycott Fowzan?S. Alkuraya 《American journal of human genetics》2015,97(4):608-615
Skeletal dysplasias are highly variable Mendelian phenotypes. Molecular diagnosis of skeletal dysplasias is complicated by their extreme clinical and genetic heterogeneity. We describe a clinically recognizable autosomal-recessive disorder in four affected siblings from a consanguineous Saudi family, comprising progressive spondyloepimetaphyseal dysplasia, short stature, facial dysmorphism, short fourth metatarsals, and intellectual disability. Combined autozygome/exome analysis identified a homozygous frameshift mutation in RSPRY1 with resulting nonsense-mediated decay. Using a gene-centric “matchmaking” system, we were able to identify a Peruvian simplex case subject whose phenotype is strikingly similar to the original Saudi family and whose exome sequencing had revealed a likely pathogenic homozygous missense variant in the same gene. RSPRY1 encodes a hypothetical RING and SPRY domain-containing protein of unknown physiological function. However, we detect strong RSPRY1 protein localization in murine embryonic osteoblasts and periosteal cells during primary endochondral ossification, consistent with a role in bone development. This study highlights the role of gene-centric matchmaking tools to establish causal links to genes, especially for rare or previously undescribed clinical entities.Keyword: matchmaking, autozygome, exome, skeletal dysplasia, mucopolysaccharidosis, craniosynostosis 相似文献
95.
Judd AS Souers AJ Wodka D Zhao G Mulhern MM Iyengar RR Gao J Lynch JK Freeman JC Falls HD Brodjian S Dayton BD Reilly RM Gintant G Limberis JT Mikhail A Leitza ST Houseman KA Diaz G Bush EN Shapiro R Knourek-Segel V Hernandez LE Marsh KC Sham HL Collins CA Kym PR 《Bioorganic & medicinal chemistry letters》2007,17(8):2365-2371
A series of potent 2-carboxychromone-based melanin-concentrating hormone receptor 1 (MCHr1) antagonists were synthesized and evaluated for hERG (human Ether-a-go-go Related Gene) channel affinity and functional blockade. Basic dialkylamine-terminated analogs were found to weakly bind the hERG channel and provided marked improvement in a functional patch-clamp assay versus previously reported antagonists of the series. 相似文献
96.
Souers AJ Iyengar RR Judd AS Beno DW Gao J Zhao G Brune ME Napier JJ Mulhern MM Lynch JK Freeman JC Wodka D Chen CJ Falls HD Brodjian S Dayton BD Diaz GJ Bush EN Shapiro R Droz BA Knourek-Segel V Hernandez LE Marsh KC Reilly RM Sham HL Collins CA Kym PR 《Bioorganic & medicinal chemistry letters》2007,17(4):884-889
The incorporation of constrained tertiary amines into an existing class of N-benzyl-4-aminopiperidinyl chromone-based MCHr1 antagonists led to the identification of a series of chiral racemic compounds that displayed good to excellent functional potency, binding affinity, and selectivity over the hERG channel. Further separation of two distinct chiral racemic compounds into their corresponding pairs of enantiomers revealed a considerable selectivity for MCHr1 for one configuration, in addition to a striking difference in oral exposure between one pair of enantiomers in diet-induced obese mice. Oral administration of the most potent compound in this class in the same animal model led to significant reduction of fat mass in a semi-chronic model for weight loss. 相似文献
97.
Waldron RT Whitelegge JP Faull KF Rozengurt E 《Biochemical and biophysical research communications》2007,356(2):361-367
Protein kinase D (PKD) phosphorylates the c-jun amino-terminal in vitro at site(s) distinct from JNK [C. Hurd, R.T. Waldron, E. Rozengurt, Protein kinase D complexes with c-jun N-terminal kinase via activation loop phosphorylation and phosphorylates the c-jun N-terminus, Oncogene 21 (2002) 2154-2160], but the sites have not been identified. Here, metabolic (32)P-labeling of c-jun protein in COS-7 cells indicated that PKD phosphorylates c-jun in vivo at a site(s) between aa 43-93, a region containing important functional elements. On this basis, the PKD-mediated phosphorylation site(s) was further characterized in vitro using GST-c-jun fusion proteins. PKD did not incorporate phosphate into Ser63 and Ser73, the JNK sites in GST-c-jun(1-89). Rather, PKD and JNK could sequentially phosphorylate distinct site(s) simultaneously. By mass spectrometry of tryptic phosphopeptides, Ser58 interposed between the JNK-binding portion of the delta domain and the adjacent TAD1 was identified as a prominent site phosphorylated in vitro by PKD. These data were further supported by kinase reactions using truncations or point-mutations of GST-c-jun. Together, these data suggest that PKD-mediated phosphorylation modulates c-jun at the level of its N-terminal functional domains. 相似文献
98.
Gabrielle Lemire Yoko A. Ito Aren E. Marshall Nicolas Chrestian Valentina Stanley Lauren Brady Mark Tarnopolsky Cynthia J. Curry Taila Hartley Wendy Mears Alexa Derksen Nadie Rioux Nataly Laflamme Harrol T. Hutchison Lynn S. Pais Maha S. Zaki Tipu Sultan Adrie D. Dane CareRare Canada Consortium Joseph G. Gleeson Frdric M. Vaz Kristin D. Kernohan Genevive Bernard Kym M. Boycott 《American journal of human genetics》2021,108(10):2017-2023
99.
Annette V. Jacobsen Catia L. Pierotti Kym N. Lowes Amanda E. Au Ying Zhang Nima Etemadi Cheree Fitzgibbon Wilhelmus J. A. Kersten Andr L. Samson Mark F. van Delft David C. S. Huang Hlne Jousset Sabroux Guillaume Lessene John Silke James M. Murphy 《Cell death & disease》2022,13(4)
Necroptosis is a form of caspase-independent programmed cell death that arises from disruption of cell membranes by the mixed lineage kinase domain-like (MLKL) pseudokinase after its activation by the upstream kinases, receptor interacting protein kinase (RIPK)-1 and RIPK3, within a complex known as the necrosome. Dysregulated necroptosis has been implicated in numerous inflammatory pathologies. As such, new small molecule necroptosis inhibitors are of great interest, particularly ones that operate downstream of MLKL activation, where the pathway is less well defined. To better understand the mechanisms involved in necroptosis downstream of MLKL activation, and potentially uncover new targets for inhibition, we screened known kinase inhibitors against an activated mouse MLKL mutant, leading us to identify the lymphocyte-specific protein tyrosine kinase (Lck) inhibitor AMG-47a as an inhibitor of necroptosis. We show that AMG-47a interacts with both RIPK1 and RIPK3, that its ability to protect from cell death is dependent on the strength of the necroptotic stimulus, and that it blocks necroptosis most effectively in human cells. Moreover, in human cell lines, we demonstrate that AMG-47a can protect against cell death caused by forced dimerisation of MLKL truncation mutants in the absence of any upstream signalling, validating that it targets a process downstream of MLKL activation. Surprisingly, however, we also found that the cell death driven by activated MLKL in this model was completely dependent on the presence of RIPK1, and to a lesser extent RIPK3, although it was not affected by known inhibitors of these kinases. Together, these results suggest an additional role for RIPK1, or the necrosome, in mediating human necroptosis after MLKL is phosphorylated by RIPK3 and provide further insight into reported differences in the progression of necroptosis between mouse and human cells.Subject terms: Kinases, Necroptosis 相似文献