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31.
32.
The R-spondin protein family 总被引:1,自引:0,他引:1
The four vertebrate R-spondin proteins are secreted agonists of the canonical Wnt/β-catenin signaling pathway. These proteins are approximately 35 kDa, and are characterized by two amino-terminal furin-like repeats, which are necessary and sufficient for Wnt signal potentiation, and a thrombospondin domain situated more towards the carboxyl terminus that can bind matrix glycosaminoglycans and/or proteoglycans. Although R-spondins are unable to initiate Wnt signaling, they can potently enhance responses to low-dose Wnt proteins. In humans, rare disruptions of the gene encoding R-spondin1 cause a syndrome of XX sex reversal (phenotypic male), palmoplantar keratosis (a thickening of the palms and soles caused by excess keratin formation) and predisposition to squamous cell carcinoma of the skin. Mutations in the gene encoding R-spondin4 cause anonychia (absence or hypoplasia of nails on fingers and toes). Recently, leucine-rich repeat-containing G-protein-coupled receptor (Lgr)4, Lgr5 and Lgr6, three closely related orphans of the leucine-rich repeat family of G-protein-coupled receptors, have been identified as receptors for R-spondins. Lgr5 and Lgr6 are markers for adult stem cells. Because R-spondins are potent stimulators of adult stem cell proliferation in vivo and in vitro, these findings might guide the therapeutic use of R-spondins in regenerative medicine. 相似文献
33.
Eduardo AVF Ramalho Jo?o LQ Silva-Filho Marina FS Cartaxo Carmelita BL Cavalcanti Moacyr JBM Rêgo Maria BM Oliveira Eduardo IC Beltr?o 《Biological research》2014,47(1)
Background
BRCA protein interacts with at least 13 different proteins that have been implicated with cancer susceptibility and loss of BRCA function is correlated to sensitivity to DNA crosslinking agents in preclinical models.Results
BRCA2 methylation frequency was 44%, p53 Pro22 allele frequency was 32% and heterozygous frequency of Arg/Pro72 genotype was 60% which could be associated as risk factor for metastasis (p = 0.046 OR = 4.190). Regarding to polymorphism of codon 249 the frequency of Arg249 allele presented 82% which was considered not statistically significant.Conclusions
There was not statistical significance to BRCA2 promoter methylation with any parameters chosen. However, our findings suggest that patients who present heterozygous genotype at codon 72 of p53 gene may have a major susceptibility to any type of metastasis and this could serve as potential auxiliary biomarker for poor prognosis. 相似文献34.
35.
Background
Phylogenetic methods which do not rely on multiple sequence alignments are important tools in inferring trees directly from completely sequenced genomes. Here, we extend the recently described Genome BLAST Distance Phylogeny (GBDP) strategy to compute phylogenetic trees from all completely sequenced plastid genomes currently available and from a selection of mitochondrial genomes representing the major eukaryotic lineages. BLASTN, TBLASTX, or combinations of both are used to locate high-scoring segment pairs (HSPs) between two sequences from which pairwise similarities and distances are computed in different ways resulting in a total of 96 GBDP variants. The suitability of these distance formulae for phylogeny reconstruction is directly estimated by computing a recently described measure of "treelikeness", the so-called δ value, from the respective distance matrices. Additionally, we compare the trees inferred from these matrices using UPGMA, NJ, BIONJ, FastME, or STC, respectively, with the NCBI taxonomy tree of the taxa under study. 相似文献36.
Henz SL Ribeiro CG Rosa A Chiarelli RA Casali EA Sarkis JJ 《Cell biology international》2006,30(3):214-220
The participation of ecto-ATP diphosphohydrolase (CD39; ecto-NTPDase) and ecto-5'-nucleotidase (CD73) activities in the nucleotide hydrolysis by salivary gland cells from rats was evaluated. We investigated the biochemical characteristics of these ectoenzymes in cells cultured from submandibular salivary glands of rats. The V(max) for the hydrolysis of ATP, ADP and AMP were 2275+/-153 (mean+/-SEM, n = 4), 941+/-96 (mean+/-SEM, n = 5) and 175+/-5 (mean+/-SEM, n = 5) nmol Pi liberated per min per mg of protein, respectively. The K(m) values for ATP, ADP and AMP were 224+/-8 microM (mean+/-SEM, n = 4), 163+/-15 microM (mean+/-SEM, n = 5) and 117+/-5 microM (mean+/-SEM, n = 5), respectively. The competition plot showed that ATP and ADP were hydrolyzed at the same active site on the enzyme. It may be postulated that the physiological role for this ecto-enzyme cascade is to terminate the action of the co-transmitter ATP, generating adenosine. 相似文献
37.
Laubinger S Zeller G Henz SR Sachsenberg T Widmer CK Naouar N Vuylsteke M Schölkopf B Rätsch G Weigel D 《Genome biology》2008,9(7):R112
Gene expression maps for model organisms, including Arabidopsis thaliana, have typically been created using gene-centric expression arrays. Here, we describe a comprehensive expression atlas, Arabidopsis thaliana Tiling Array Express (At-TAX), which is based on whole-genome tiling arrays. We demonstrate that tiling arrays are accurate
tools for gene expression analysis and identified more than 1,000 unannotated transcribed regions. Visualizations of gene
expression estimates, transcribed regions, and tiling probe measurements are accessible online at the At-TAX homepage. 相似文献
38.
Angstrom J; Teneberg S; Milh MA; Larsson T; Leonardsson I; Olsson BM; Halvarsson MO; Danielsson D; N aslund I; Ljungh A; Wadstrom T; Karlsson KA 《Glycobiology》1998,8(4):297-309
The possible role of glycosphingolipids as adhesion receptors for the human
gastric pathogen Helicobacter pylori was examined by use of radiolabeled
bacteria, or protein extracts from the bacterial cell surface, in the
thin-layer chromatogram binding assay. Of several binding specificities
found, the binding to lactosylceramide is described in detail here, the
others being reported elsewhere. By autoradiography a preferential binding
to lactosylceramide having sphingosine/phytosphingosine and 2-D hydroxy
fatty acids was detected, whereas lactosylceramide having sphingosine and
nonhydroxy fatty acids was consistently nonbinding. A selective binding of
H. pylori to lactosylceramide with phytosphingosine and 2-D hydroxy fatty
acid was obtained when the different lactosylceramide species were
incorporated into liposomes, but only in the presence of cholesterol,
suggesting that this selectivity may be present also in vivo . Importantly,
lactosylceramide with sphingosine and hydroxy fatty acids does not bind in
this assay. Furthermore, a lactosylceramide-based binding pattern obtained
for different trisaccharide glycosphingolipids is consistent with the
assumption that this selectivity is due to binding of a conformation of
lactosylceramide in which the oxygen of the 2-D fatty acid hydroxyl group
forms a hydrogen bond with the Glc hydroxy methyl group, yielding an
epitope presentation different from other possible conformers. An
alternative conformation that may come into consideration corresponds to
the crystal structure found for cerebroside, in which the fatty acid
hydroxyl group is free to interact directly with the adhesin. By isolating
glycosphingolipids from epithelial cells of human stomach from seven
individuals, a binding of H.pylori to the diglycosylceramide region of the
non-acid fraction could be demonstrated in one of these cases. Mass
spectrometry showed that the binding-active sample contained
diglycosylceramides with phytosphingosine and 2-D hydroxy fatty acids with
16-24 carbon atoms in agreement with the results related above.
相似文献
39.
A 522-base-long Y-chromosomal sequence was isolated from a BALB/c genomic
library and was designated "BF046." It is repeated about 200 times in the
male genome, and a difference was detected between the Mus musculus
musculus and the M. m. domesticus type Y chromosomes. BF046- related
sequences were present over the entire length of the Y chromosome as
visualized by in situ hybridization. Southern blot analysis against DNAs
isolated from eight species in the genus Mus showed that BF046-related
sequences were amplified in the Y chromosomes of three closely related
species: M. musculus, M. spicilegus, and M. spretus. To gain insight into
the stability of the BF046 sequence family, we isolated 18 additional
clones from these three mouse species and compared their sequences. The M.
musculus sequences differed from the M. spicilegus and M. spretus sequences
by two indels. The remaining parts of the sequences were very similar, but
both parsimony and distance-based analytical methods divided the sequences
into the same four subgroups, with each species having its own subgroup(s).
Thus, the Y chromosomes of M. musculus, M. spicilegus, and M. spretus can
be distinguished from one another.
相似文献
40.
Distinct expression patterns of natural antisense transcripts in Arabidopsis 总被引:2,自引:0,他引:2
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Henz SR Cumbie JS Kasschau KD Lohmann JU Carrington JC Weigel D Schmid M 《Plant physiology》2007,144(3):1247-1255