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1.
《European journal of cell biology》2019,98(5-8):151044
Cripto-1 is a protein participating in tissue orientation during embryogenesis but has also been implicated in a wide variety of cancers, such as colon, lung and breast cancer. Cripto-1 plays a role in the regulation of different pathways, including TGF-β/Smad and Wnt/β-catenin, which are highly associated with cell migration both during embryonal development and cancer progression. Little is known about the detailed subcellular localization of cripto-1 and how it participates in the directional movement of cells. In this study, the subcellular localization of cripto-1 in glioblastoma cells was investigated in vitro with high-resolution microscopy techniques. Cripto-1 was found to be localized to dynamic and shed filopodia and transported between cells through tunneling nanotubes. Our results connect the refined subcellular localization of cripto-1 to its functions in cellular orientation and migration. 相似文献
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M. J. Higgins D. Loiselle T. A. Haystead L. M. Graves 《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):850-857
We investigated the interacting proteins and intracellular localization of CTP synthetase 1 (CTPS1) in mammalian cells. CTPS1 interacted with a GST- peptidyl prolyl isomerase, Pin1 fusion (GST-Pin1) in a Ser 575 (S575) phosphorylation-dependent manner. Immunoprecipitation experiments demonstrated that CTPS1 also bound tubulin, and thirteen additional coimmunoprecipitating proteins were identified by mass spectrometry. Immunolocalization experiments showed that tubulin and CTPS1 colocalized subcellularly. Taxol treatment enhanced this but cotreatment of cells with the CTPS inhibitor, cyclopentenyl cytosine (CPEC), and taxol failed to disrupt the colocalization. Thus, these studies provide novel information on the potential interacting proteins that may regulate CTPS1 function or intracellular localization. 相似文献
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A. S. Paschoa M. E. Wrenn N. P. Singh F. W. Bruenger S. C. Miller M. Cholewa K. W. Jones 《Biological trace element research》1987,13(1):275-282
Several geological formations of the Utah-Colorado mining region mined for uranium ore during and after World War II had been
mined earlier for vanadium. Therefore, most miners and millers from that region were exposed to those metals’ ores or tailings
at one time or another. Preliminary investigation to determine uranium and vanadium retained in the lungs of a former uranium
miner and miller from this region, who died of lung cancer (mesothelioma), showed a high nonuniform distribution of vanadium.
This observation led to the hypothesis that the vanadium content in the lungs could be associated with inhaled particles.
Further examination of spectra of characteristic X-rays obtained by scanning particle-induced X-ray emission (microPIXE) of
an autopsy sample of this lung indicated that vanadium was indeed present in localized sites within the 20-μm spatial resolution
of the proton beam. This work points out that the microPIXE-RBS (Rutherford backscattering) test for vanadium can be used
for site localization of inhaled particles retained in the lungs. Further studies are in progress to: (i) locate uranium-bearing
particles in lung tissues of former uranium miners and millers; and (ii) evaluate the local doses of alpha radiation received
from these particles. 相似文献
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Immuno-gold labelling using a monoclonal antibody (PCBC3) with a primary specificity for -L-arabinofuranosyl residues was used to locate these residues in pollen tubes of Nicotiana alata grown in vivo. The antibody bound to the outer fibrillar layer of the pollen-tube wall: the inner, non-fibrillar wall layer was not labelled. Cytoplasmic vesicles (0.2 m diameter) were also labelled. The antibody may bind to an arabinan in the pollen-tube wall. 相似文献
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A ribonuclease which was previously shown to be located in isolated vacuoles from suspension-cultured cells of tomato (Lycopersicon esculentum L.; Abel and Glund 1986, Physiol. Plant. 66, 79–86) has been purified to near homogeneity. Purification was up to 55000-fold with a yield of about 20%. The vacuolar origin of the protein was evidenced by comparing its electrophoretic mobility, isoelectric point, pH-optimum for activity and other properties with that of the RNA-degrading activity present in isolated vacuoles. The molecular weight of the native single polypeptide chain was estimated at 17500 and 20300 by gel filtration and sedimentation analysis, respectively. The enzyme hydrolyzed only single-stranded RNA with a mode of action that was endonucleolytic. The vacuolar ribonuclease had no requirement for divalent metal ions, and did not exhibit phosphomonoesterase (EC 3.1.3.1; EC 3.1.3.2) and phosphodiesterase (EC 3.1.15.1; EC 3.1.16.1) activity. The specificity of the enzyme has been studied by using homopolyribonucleotides as substrates. The end-products obtained were the respective nucleoside 2:3-cyclic monophosphates and, to minor extents, the corresponding nucleoside 3(2)-monophosphates. According to these observations, the vacuolar ribonuclease from tomato can be classified as ribonuclease I (EC 3.1.27.1).Abbreviations DEAE
diethylaminoethyl
- RNase
ribonuclease
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis 相似文献
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Vacuoles of tobacco mesophyll and of suspension-cultured cells were isolated in order to study the localization of peroxidase isoenzymes. Only basic peroxidases were detectable by electrophoretic separation of the vacuolar sap. Some of the basic peroxidases have formerly been described as an ionically bound cell-wall fraction. This fraction, however, was found to be an artifact produced by incomplete cell breakage. Reinvestigation of isolated cell walls confirmed that mainly acidic peroxidases are localized in the cell walls where they move freely or are bound. As a consequence of former and present results we think it probable that all of the peroxidase isoenzymes are secretory proteins because they have to be transported from the sites of synthesis in the cytoplasm to the sites of function, the extracytoplasmic spaces, cell wall (acidic peroxidases), and vacuole (basic peroxidases).Abbreviation ER
endoplasmic reticulum
- PAGE
polyacrylamide gel electrophoresis 相似文献
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Ferredoxin-NADP reductase from Euglena gracilis Klebs var. Bacillaris Cori purified to apparent homogeneity, yields a typical 36 kDa and an unusual 15 kDa polypeptide on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, exhibits a typical flavoprotein spectrum, contains FAD, and catalyzes NADPH-dependent iodonitrotetrazolium-violet diaphorase, NADPH-specific ferredoxin-dependent cytochrome-c-550 reductase and NADPH-NAD transhydrogenase activities. Rabbit antibody to the purified FNR blocks these activities specifically and also blocks the iodonitrotetrazolium-violet diaphorase activity of Euglena chloroplasts completely. The low iodonitrotetrazolium-violet diaphorase activity in the plastidless mutant, W10BSmL, is mitochondrial and is not specifically blocked by the ferredoxin-NADP reductase antibody. Dark-grown non-dividing (resting) wild-type Euglena cells show a 4-fold increase in ferredoxin-NADP reductase activity during greening at 970 lx. Half of the low ferredoxin-NADP reductase activity in dark-grown cells is initially soluble, but by the end of chloroplast development nearly all of the enzyme is membrane-bound. The binding of ferredoxin-NADP reductase on exposure to light correlates with the extent of thylakoid membrane formation. Immunoblots of wild-type extracts during greening indicate that the 15 kDa polypeptide increases in the same manner as the extent of reductase binding to thylakoid membranes. 相似文献