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排序方式: 共有233条查询结果,搜索用时 234 毫秒
1.
Niyati Jain Christopher E. Morgan Brittany D. Rife Marco Salemi Blanton S. Tolbert 《The Journal of biological chemistry》2016,291(5):2331-2344
Splicing patterns in human immunodeficiency virus type 1 (HIV-1) are maintained through cis regulatory elements that recruit antagonistic host RNA-binding proteins. The activity of the 3′ acceptor site A7 is tightly regulated through a complex network of an intronic splicing silencer (ISS), a bipartite exonic splicing silencer (ESS3a/b), and an exonic splicing enhancer (ESE3). Because HIV-1 splicing depends on protein-RNA interactions, it is important to know the tertiary structures surrounding the splice sites. Herein, we present the NMR solution structure of the phylogenetically conserved ISS stem loop. ISS adopts a stable structure consisting of conserved UG wobble pairs, a folded 2X2 (GU/UA) internal loop, a UU bulge, and a flexible AGUGA apical loop. Calorimetric and biochemical titrations indicate that the UP1 domain of heterogeneous nuclear ribonucleoprotein A1 binds the ISS apical loop site-specifically and with nanomolar affinity. Collectively, this work provides additional insights into how HIV-1 uses a conserved RNA structure to commandeer a host RNA-binding protein. 相似文献
2.
Anonymous nuclear DNA markers in the American oyster and their implications for the heterozygote deficiency phenomenon in marine bivalves 总被引:4,自引:0,他引:4
A puzzling population-genetic phenomenon widely reported in allozyme
surveys of marine bivalves is the occurrence of heterozygote deficits
relative to Hardy-Weinberg expectations. Possible explanations for this
pattern are categorized with respect to whether the effects should be
confined to protein-level assays or are genomically pervasive and expected
to be registered in both protein- and DNA-level assays. Anonymous nuclear
DNA markers from the American oyster were employed to reexamine the
phenomenon. In assays based on the polymerase chain reaction (PCR), two
DNA-level processes were encountered that can lead to artifactual genotypic
scorings: (a) differential amplification of alleles at a target locus and
(b) amplification from multiple paralogous loci. We describe symptoms of
these complications and prescribe methods that should generally help to
ameliorate them. When artifactual scorings at two anonymous DNA loci in the
American oyster were corrected, Hardy-Weinberg deviations registered in
preliminary population assays decreased to nonsignificant values.
Implications of these findings for the heterozygote-deficit phenomenon in
marine bivalves, and for the general development and use of PCR-based
assays, are discussed.
相似文献
3.
4.
Marta Clariano Vanda Marques João Vaz Salma Awam Marta B. Afonso Maria Jesus Perry Cecília MP Rodrigues 《化学与生物多样性》2023,20(3):e202300222
Curcumin has a plethora of biological properties, making this compound potentially effective in the treatment of several diseases, including cancer. However, curcumin clinical use is compromised by its poor pharmacokinetics, being crucial to find novel analogs with better pharmacokinetic and pharmacological properties. Here, we aimed to evaluate the stability, bioavailability and pharmacokinetic profiles of monocarbonyl analogs of curcumin. A small library of monocarbonyl analogs of curcumin 1a–q was synthesized. Lipophilicity and stability in physiological conditions were both assessed by HPLC-UV, while two different methods assessed the electrophilic character of each compound monitored by NMR and by UV-spectroscopy. The potential therapeutic effect of the analogs 1a–q was evaluated in human colon carcinoma cells and toxicity in immortalized hepatocytes. Our results showed that the curcumin analog 1e is a promising agent against colorectal cancer, with improved stability and efficacy/safety profile. 相似文献
5.
Nonsyndromic cleft lip with or without cleft palate: evidence of linkage to BCL3 in 17 multigenerational families. 总被引:11,自引:6,他引:5 下载免费PDF全文
J Stein J B Mulliken S Stal D L Gasser S Malcolm R Winter S H Blanton C Amos E Seemanova J T Hecht 《American journal of human genetics》1995,57(2):257-272
Nonsyndromic cleft lip with or without cleft palate (CL/P) is a common craniofacial developmental defect. Recent segregation analyses have suggested that major genes play a role in the etiology of CL/P. Linkage to 22 candidate genes was tested in 11 multigenerational families with CL/P, and 21 of these candidates were excluded. APOC2, 19q13.1, which is linked to the proto-oncogene BCL3, gave suggestive evidence for linkage to CL/P. The study was expanded to include a total of 39 multigenerational CL/P families. Linkage was tested in all families, using an anonymous marker, D19S178, and intragenic markers in BCL3 and APOC2. Linkage was tested under two models, autosomal dominant with reduced penetrance and affecteds only. Homogeneity testing on the two-point data gave evidence of heterogeneity at APOC2 under the affecteds-only model. Both models showed evidence of heterogeneity, with 43% of families linked at zero recombination to BCL3 when marker data from BCL3 and APOC2 were included. A maximum multipoint LOD score of 7.00 at BCL3 was found among the 17 families that had posterior probabilities > = 50% in favor of linkage. The transmission disequilibrium test provided additional evidence for linkage with the 3 allele of BCL3 more often transmitted to affected children. These results suggest that BCL3, or a nearby gene, plays a role in the etiology of CL/P in some families. 相似文献
6.
Sampling properties of DNA sequence data in phylogenetic analysis 总被引:26,自引:6,他引:20
We inferred phylogenetic trees from individual genes and random samples of
nucleotides from the mitochondrial genomes of 10 vertebrates and compared
the results to those obtained by analyzing the whole genomes. Individual
genes are poor samples in that they infrequently lead to the whole-genome
tree. A large number of nucleotide sites is needed to exactly determine the
whole-genome tree. A relatively small number of sites, however, often
results in a tree close to the whole-genome tree. We found that blocks of
contiguous sites were less likely to lead to the whole-genome tree than
samples composed of sites drawn individually from throughout the genome.
Samples of contiguous sites are not representative of the entire genome, a
condition that violates a basic assumption of the bootstrap method as it is
applied in phylogenetic studies.
相似文献
7.
8.
9.
R A Blanton M D Coltrera A M Gown C L Halbert J K McDougall 《Cell growth & differentiation》1992,3(11):791-802
Monolayer cultures of human foreskin and ectocervical epithelial cells were infected with retroviral vectors expressing HPV16 oncogenes, selected for G418 resistance, and cultured organotypically so that they reformed the fully differentiated, stratified squamous tissues from which they were originally derived. Expression of HPV16 E7 prevented cell cycle withdrawal in the suprabasal layers of these stratified cultures but had no effect on terminal differentiation. Cultures expressing E7 alone and those coexpressing E6 and E7 were identical in terms of suprabasal proliferation and terminal differentiation, but they differed in expression of the endogenous tumor suppressor protein p53. Immunohistochemically detectable p53 protein localized to the proliferative compartment in normal and E7-containing cultures but was undetectable in those cultures which coexpressed E6 and E7. This result suggests that E7-induced suprabasal proliferation is independent of the steady-state level of p53. 相似文献
10.
Conclusions and summary The experiments described in this paper tend to show that the relation between stainability and electromotive forces: + basophilic substance / acidophilic substance — holds not only for fats but likewise for esters, alcohols, hydrocarbons, etc., in short for a large number of substances which bear just a remote relationship to tissue constitutents. Exceptions to this rule are very rare and are hardly found prevailing in tissue.In these experiments esters, alcohol, and other substances were rendered basophilic by the addition of a water insoluble acid or else acidophilic by the addition of a water insoluble base; measurements of the electromotive force were made. The system measured was the following:
The measurements were performed by combining each ester, alcohol, or other fluid with phenol using the apparatus described in part I of this report. The difference between two such measurements may be considered to be the electromotive force of such a cell. This was demonstrated previously be means of measurements with triacetin. The reason for this is that the electromotive forces of such battery systems, as those described, are located almost entirely at the phase boundary between the aqueous solution and the water immiscible fluid.To Dr. G. W.Crile the writers wish to express their appreciation for his kind interest in the progress of this work. 相似文献