排序方式: 共有27条查询结果,搜索用时 93 毫秒
1.
Peptide antisera to human colony-stimulating factor 1 receptor detect ligand-induced conformational changes and a binding site for phosphatidylinositol 3-kinase. 总被引:10,自引:4,他引:6
下载免费PDF全文
![点击此处可从《Molecular and cellular biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A peptide antiserum (anti-A) directed to the intracellular, juxtamembrane region (residues 552 to 574) of the human colony-stimulating factor 1 receptor (CSF-1R) precipitated only ligand-activated, native receptors from solution but bound to unstimulated forms after their denaturation. Two peptide antisera (anti-KI1 and -KI2), directed to residues 679 to 700 and 701 to 721, respectively, in the CSF-1R kinase insert (KI) domain and including mapped sites of ligand-induced phosphorylation at Tyr-699 and Tyr-708, bound at least 80% of the receptor molecules expressed in either CSF-1-stimulated or unstimulated cells. Immune complexes formed with anti-KI1, anti-A, or a peptide antiserum to the CSF-1R carboxyl terminus (anti-C-ter) coprecipitated CSF-1R complexed to a phosphatidylinositol 3-kinase (PtdIns 3-K) from CSF-1-stimulated cells, whereas anti-KI2 serum did not. In an in vitro assay, binding of CSF-1R to PtdIns 3-K required receptor tyrosine phosphorylation but not CSF-1R-mediated phosphorylation of the lipid kinase, and the association was specifically blocked by anti-KI2 or antibodies to phosphotyrosine. Neither anti-KI1, anti-A, nor anti-C-ter serum inhibited binding. We conclude that (i) only a minority of ligand-activated receptors form a stable complex with PtdIns 3-K in vivo, (ii) efficient binding of the lipid kinase requires receptor tyrosine phosphorylation within the CSF-1R KI domain, and (iii) a region within the KI domain defined by residues 701 to 721 at least partially overlaps the PtdIns 3-K binding site. 相似文献
2.
Carcinoid tumors are low-grade malignant tumors that arise from neuroendocrine cells. Primary renal carcinoid tumors are extremely uncommon. They seem to be more indolent than renal cell carcinomas, although metastases to regional lymph nodes, liver, and bone have been described. The presence of metastases seems to indicate a more malignant course; however, even with metastases a patient might live for 3 or 4 years. Renal carcinoid tumors should be managed by radical or partial nephrectomy, and good outcomes have been obtained for organ-confined disease after radical excision. Conventional methods of imaging are inadequate for detecting smaller carcinoids, so somatostatin receptor scintigraphy should complement computed tomography and magnetic resonance imaging when searching for occult or metastatic disease. Close follow-up after surgery is necessary. 相似文献
3.
4.
5.
Effects of the emerald ash borer invasion on the community composition of arthropods associated with ash tree boles in Maryland,U.S.A.
下载免费PDF全文
![点击此处可从《Agricultural and Forest Entomology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
David E. Jennings Jian J. Duan Dick Bean Kimberly A. Rice Gaye L. Williams Steven K. Bell Aaron S. Shurtleff Paula M. Shrewsbury 《Agricultural and Forest Entomology》2017,19(2):122-129
6.
7.
THE BREEDING SYSTEM IN PRIMULA VERIS L. 总被引:4,自引:2,他引:2
8.
9.
Characterization of development and artemisinin biosynthesis in self-pollinated <Emphasis Type="Italic">Artemisia annua</Emphasis> plants 总被引:1,自引:0,他引:1
Artemisia annua L. is the only natural resource that produces artemisinin (Qinghaosu), an endoperoxide sesquiterpene lactone used in the
artemisinin-combination therapy of malaria. The cross-hybridization properties of A. annua do not favor studying artemisinin biosynthesis. To overcome this problem, in this study, we report on selection of self-pollinated
A. annua plants and characterize their development and artemisinin biosynthesis. Self-pollinated F2 plants selected were grown under
optimized growth conditions, consisting of long day (16 h of light) and short day (9 h of light) exposures in a phytotron.
The life cycles of these plants were approximately 3 months long, and final heights of 30–35 cm were achieved. The leaves
on the main stems exhibited obvious morphological changes, from indented single leaves to odd, pinnately compound leaves.
Leaves and flowers formed glandular and T-shaped trichomes on their surfaces. The glandular trichome densities increased from
the bottom to the top leaves. High performance liquid chromatography–mass spectrometry-based metabolic profiling analyses
showed that leaves, flowers, and young seedlings of F2 plants produced artemisinin. In leaves, the levels of artemisinin increased
from the bottom to the top of the plants, showing a positive correlation to the density increase of glandular trichomes. RT-PCR
analysis showed that progeny of self-pollinated plants expressed the amorpha-4, 11-diene synthase (ADS) and cytochrome P450
monooxygenase 71 AV1 (CYP71AV1) genes, which are involved in artemisinin biosynthesis in leaves and flowers. The use of self-pollinated
A. annua plants will be a valuable approach to the study of artemisinin biosynthesis. 相似文献
10.
Logares R Rengefors K Kremp A Shalchian-Tabrizi K Boltovskoy A Tengs T Shurtleff A Klaveness D 《Microbial ecology》2007,53(4):549-561
The agents driving the divergence and speciation of free-living microbial populations are still largely unknown. We investigated
the dinoflagellate morphospecies Scrippsiella hangoei and Peridinium aciculiferum, which abound in the Baltic Sea and in northern temperate lakes, respectively. Electron microscopy analyses showed significant
interspecific differences in the external cellular morphology, but a similar plate pattern in the characteristic dinoflagellate
armor. Experimentally, S. hangoei grew in a wide range of salinities (0–30), whereas P. aciculiferum only grew in low salinities (0–3). Despite these phenotypic differences and the habitat segregation, molecular analyses showed
identical ribosomal DNA sequences (ITS1, ITS2, 5.8S, SSU, and partial LSU) for both morphospecies. Yet, a strong interspecific
genetic isolation was indicated by amplified fragment length polymorphism (F
ST = 0.76) and cytochrome b (cob) sequence divergence (∼1.90%). Phylogenetic reconstructions based on ribosomal (SSU, LSU) and mitochondrial (cob) DNA indicated a recent marine ancestor for P. aciculiferum. In conclusion, we suggest that the lacustrine P. aciculiferum and the marine-brackish S. hangoei diverged very recently, after a marine–freshwater transition that exposed the ancestral populations to different selective
pressures. This hypothetical scenario agrees with mounting data indicating a significant role of natural selection in the
divergence of free-living microbes, despite their virtually unrestricted dispersal capabilities. Finally, our results indicate
that identical ITS rDNA sequences do not necessarily imply the same microbial species, as commonly assumed. 相似文献