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991.
We have developed a strategy to preferentially label the N-terminal alpha-amino groups of intact proteins allowing the internal epsilon-amino groups to remain free to react with chemical crosslinking reagents. The convergence of these methodologies allows biotinylated ligands to bind to their receptors within the cell membrane followed by removal of the crosslinked complex from cell lysate. This technique allows for the isolation of protein complexes in an MS-compatible system, thus providing a tool for furthering our understanding of signal transduction. 相似文献
992.
Tang LY Deng N Wang LS Dai J Wang ZL Jiang XS Li SJ Li L Sheng QH Wu DQ Li L Zeng R 《Molecular & cellular proteomics : MCP》2007,6(11):1952-1967
The complexity of canonical Wnt signaling comes not only from the numerous components but also from multiple post-translational modifications. Protein phosphorylation is one of the most common modifications that propagates signals from extracellular stimuli to downstream effectors. To investigate the global phosphorylation regulation and uncover novel phosphoproteins at the early stages of canonical Wnt signaling, HEK293 cells were metabolically labeled with two stable isotopic forms of lysine and were stimulated for 0, 1, or 30 min with purified Wnt3a. After phosphoprotein enrichment and LC-MS/MS analysis, 1057 proteins were identified in all three time points. In total 287 proteins showed a 1.5-fold or greater change in at least one time point. In addition to many known Wnt signaling transducers, other phosphoproteins were identified and quantitated, implicating their involvement in canonical Wnt signaling. k-Means clustering analysis showed dynamic patterns for the differential phosphoproteins. Profile pattern and interaction network analysis of the differential phosphoproteins implicated the possible roles for those unreported components in Wnt signaling. Moreover 100 unique phosphorylation sites were identified, and 54 of them were quantitated in the three time points. Site-specific phosphopeptide quantitation revealed that Ser-20 phosphorylation on RRM2 increased upon 30-min Wnt3a stimulation. Further studies with mutagenesis, the Wnt reporter gene assay, and RNA interference indicated that RRM2 functioned downstream of beta-catenin as an inhibitor of Wnt signaling and that Ser-20 phosphorylation of RRM2 counteracted its inhibition effect. Our systematic profiling of dynamic phosphorylation changes responding to Wnt3a stimulation not only presented a comprehensive phosphorylation network regulated by canonical Wnt signaling but also found novel molecules and phosphorylation involved in Wnt signaling. 相似文献
993.
994.
Summary Pretarsal orbicularis oculi muscle (POOM) is an important structure of eyelid movement in human. The aim of this study was
to investigate fiber histomorphology and myosin heavy chain (MyHC) isoform composition of adult POOM, and to clarify their
age-related changes. Eyelid specimens from 58 subjects (age range, 21 to 91 years) were collected during upper blepharoplasty
procedures. Serial cross sections of POOM were ATPase-stained and examined under miscroscope. Quantitative measures of muscle
fiber size and fiber type distribution were obtained in 35 subjects with adequate fiber cross sections. Relative MyHC isoform
contents of POOM were retrieved by gel electrophoresis in all 58 subjects. Examination of the histochemical staining revealed
an abundance of type II fiber ( >85%) in human POOM, with more type IIX than IIA fibers. Decreased mean area of all fibers
and type IIA fibers were noted in the old group when compared to the young. As for MyHC analysis, the relative content of
MyHC isoforms exhibited an order of IIX > IIA > I, and the relative MyHC IIA content showed a negative correlation with age.
Comparing with previous studies of limb or masticatory muscles, adult POOM exhibits a unique fiber and MyHC composition, as
well as a different aging pattern. 相似文献
995.
Three-dimensional quantitative structure-activity relationship (3D-QSAR) analyses using CoMFA and CoMSIA methods were conducted
on a series of fluoropyrrolidine amides as dipeptidyl peptidase IV (DP-IV) inhibitors. The selected ligands were docked into
the binding site of the 3D model of DP-IV using the GOLD software, and the possible interaction models between DP-IV and the
inhibitors were obtained. Based on the binding conformations of these fluoropyrrolidine amides and their alignment inside
the binding pocket of DP-IV, predictive 3D-QSAR models were established by CoMFA and CoMSIA analyses, which had conventional
r
2 and cross-validated coefficient values () up to 0.982 and 0.555 for CoMFA and 0.953 and 0.613 for CoMSIA, respectively. The predictive ability of these models was
validated by six compounds that were in the testing set. Structure-based investigations and the final 3D-QSAR results provide
the guide for designing new potent inhibitors. 相似文献
996.
Deng Chen Hong Hu Wenhui He Shimei Zhang Mengxi Tang Shikun Xiang Caiyun Liu Xuan Cai Ahmed Hendy Muhammad Kamran Hao Liu Lu Zheng Junbing Huang Xiao-Lin Chen Junjie Xing 《Molecular Plant Pathology》2022,23(1):133-147
Endocytosis plays key roles during infection of plant-pathogenic fungi, but its regulatory mechanisms are still largely unknown. Here, we identified a putative endocytosis-related gene, PAL1, which was highly expressed in appressorium of Magnaporthe oryzae, and was found to be important for appressorium formation and maturation. Deletion of PAL1 significantly reduced the virulence of M. oryzae due to defects in appressorial penetration and invasive growth in host cells. The Pal1 protein interacted and colocalized with the endocytosis protein Sla1, suggesting it is involved in endocytosis. The Δpal1 mutant was significantly reduced in appressorium formation, which was recovered by adding exogenous cAMP and 3-isobutyl-1-methylxanthine (IBMX). Moreover, the phosphorylation level of Pmk1 in Δpal1 was also reduced, suggesting Pal1 functions upstream of both the cAMP and Pmk1 signalling pathways. As a consequence, the utilization of glycogen and lipid, appressorial autophagy, actin ring formation, localization of septin proteins, as well as turgor accumulation were all affected in the Δpal1 mutant. Taken together, Pal1 regulates cAMP and the Pmk1 signalling pathway for appressorium formation and maturation to facilitate infection of M. oryzae. 相似文献
997.
998.
Planktonic bacterial and microeukaryotic communities play important roles in biogeochemical cycles, but their biogeographic patterns and community assembly processes in large damming rivers still remain unclear. In this study, 16S rRNA and 18S rRNA coding genes were used for sample sequencing analysis of planktonic bacterial and microeukaryotic communities in the upper Yangtze River. The upper Yangtze River was divided into dam-affected zones and river zones based on the influence of dams. The results showed that there were significant differences in the bacterial and microeukaryotic communities between the two zones and that dams significantly reduced the α-diversity of the bacterial communities. Co-occurrence network analysis indicated that networks in the river zone were denser than those in the dam-affected zone. The relationships among species in bacterial networks were more complex than those in microeukaryotic networks. Dispersal limitation and ecological drift were the main processes influencing planktonic bacterial and microeukaryotic communities in the dam-affected zone respectively, whereas the role of deterministic processes increased in the river zone. Anthropogenic activities and hydraulic conditions affected suspended sediment and controlled microbial diversity in the river zone. These results suggest that dams impact planktonic bacteria more strongly than planktonic microeukaryotes, indicating that the distribution patterns and processes of the bacterial and microeukaryotic communities in large rivers are significantly different. 相似文献
999.
Pfingstl Tobias Wagner Maximilian Baumann Julia Neethling Jan Andries Bardel-Kahr Iris Hugo-Coetzee Elizabeth A. 《Organisms Diversity & Evolution》2022,22(3):789-801
Organisms Diversity & Evolution - The South African coast is known to harbor four different species of intertidal oribatid mites and their distribution strongly correlates with marine... 相似文献
1000.