Abstract:
:When a Euglena gracilis in a Ca2+-containing medium is impaled with a microelectrode, the flagellum is instantly ejected. In a Ca2+-free medium to which 1 mM EGTA has been added, the flagellum remains attached to the organism, but it loses activity upon impalement. Externally added ATP at a concentration of 10 mM will sustain normal flagellar activity (at approximately 20 Hz) of an impaled Euglena. If negative direct current of several tenths of a microamp is injected through the impaling microelectrode, the flagellar activity is stopped or much reduced. When the current injection is turned off the flagellum returns to its initial activity. This cycle can be repeated many times on the same animal, independent of whether Mg2+ is present in the external medium or not. If 1 micrometer of gramicidin is added to Ca2+-free medium containing 1 mM EGTA and 10 mM ATP, the flagellar activity becomes dependent on external Mg2+. Without external Mg2+ no flagellar activity is present after one or two current injection cycles as described above. With 1 mM Mg2+ present in the external medium many cycles (up to 10) can be produced. This Mg2+-dependent flagellar activity shows a smooth dependence on the amount of current injected. Observations taken by high speed cinemicrography show that in the third injection cycle the average frequency of the flagellar motion is 16-3 Hz at 0 muA, is 8 Hz at 0-2 muA, and is approximately 0 at 0-6 muA of negative current. The injection of positive current results in an increase in flagellar frequency dependent on the amount of current injected. The data indicate that the control of motility of Euglena flagella is dependent on an electrically activated Mg2+ pump.
journal_name
J Cell Scijournal_title
Journal of cell scienceauthors
Nichols KM,Rikmenspoel Rsubject
Has Abstractpub_date
1977-02-01 00:00:00pages
211-25eissn
0021-9533issn
1477-9137journal_volume
23pub_type
杂志文章abstract::Two isoforms of laminin were extracted from human placenta by neutral buffer containing EDTA, copurified through several steps and finally separated by Mono Q anion exchange chromatography. One variant consisted of disulphide-linked 340, 230 and 190 kDa subunits, which were identified by immunoblotting as Am, B1e and ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1994-01-01 00:00:00
abstract::The intraerythrocytic developmental cycle of Plasmodium falciparum is completed with the release of up to 32 invasive daughter cells, the merozoites, into the blood stream. Before release, the final step of merozoite development is the assembly of the cortical pellicle, a multi-layered membrane structure. This unique ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.181230
更新日期:2016-02-15 00:00:00
abstract::Human erythrocytes suspended in buffered isotonic saline were frozen to the temperature of liquid nitrogen at various cooling rates of 3, 140, 700, 1800, 3500, 8000 and 11 500 deg. C/min. The membrane ultrastructure in the frozen state and the extent of haemolysis after thawing were examined at each cooling rate. As t...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1981-06-01 00:00:00
abstract::We investigated mechanisms of the p73alpha-mediated repression of the platelet-derived growth factor beta-receptor (PDGFRB) promoter caused by its interaction with NF-Y. Treatment of cells with the histone deacetylase (HDAC) inhibitor, Trichostatin A, increases PDGFRB promoter activity through the CCAAT motif and coun...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.01384
更新日期:2004-10-15 00:00:00
abstract::MACF1 (microtubule actin crosslinking factor), also called ACF7 (actin crosslinking family 7) is a cytoskeletal linker protein that can associate with both actin filaments and microtubules. We have identified a novel alternatively spliced isoform of MACF1. We named this isoform MACF1b and renamed the original isoform ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.02510
更新日期:2005-08-15 00:00:00
abstract::The regulation of mitochondrial dynamics by the GTPase OPA1, which is located at the inner mitochondrial membrane, is crucial for adapting mitochondrial function and preserving cellular health. OPA1 governs the delicate balance between fusion and fission in the dynamic mitochondrial network. A disturbance of this bala...
journal_title:Journal of cell science
pub_type: 杂志文章,评审
doi:10.1242/jcs.159186
更新日期:2016-06-15 00:00:00
abstract::Cell migration and invasion play a crucial role during normal and pathological development. The expression of several members of the Ets family of transcription factors has been shown to correlate with the occurrence of these processes. In the present study, we investigated the effect of the expression of Ets1-DB, the...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1998-06-01 00:00:00
abstract::Recently isolated trophoblasts express nitric oxide synthase 2 (NOS-2) and cyclooxygenase 2 (COX-2), decreasing the levels of the corresponding mRNAs when the cells were maintained in culture. The sustained expression of COX-2 and NOS-2 in trophoblasts was dependent on the activation of nuclear factor kappaB (NF-kappa...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1999-09-01 00:00:00
abstract::Human peripheral blood eosinophils attach to and flatten down onto antibody-coated surfaces and subsequently degranulate. An antibody-coated surface was prepared by treating a layer of agar, containing tetanus toxoid antigen and eosinophil chemotactic factor (ECF), with human anti-tetanus immunoglobin. Changes in eosi...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1982-08-01 00:00:00
abstract::Podosomes are highly dynamic actin-based structures commonly found in motile and invasive cells such as macrophages, osteoclasts and vascular smooth muscle cells. Here, we have investigated the role of caldesmon, an actin-binding protein, in the formation of podosomes in aortic smooth muscle A7r5 cells induced by the ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.02881
更新日期:2006-05-01 00:00:00
abstract::Recent evidence suggests that organization of the extracellular matrix (ECM) into aligned fibrils or fibril-like ECM topographies promotes rapid migration in fibroblasts. However, the mechanisms of cell migration that are altered by these changes in micro-environmental topography remain unknown. Here, using 1D fibrill...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.098806
更新日期:2012-05-01 00:00:00
abstract::Mammalian, or mechanistic, target of rapamycin complex 2 (mTORC2) regulates a variety of vital cellular processes, and its aberrant functioning is often associated with various diseases. Rictor is a peculiar and distinguishing mTORC2 component playing a pivotal role in controlling its assembly and activity. Among exta...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.236505
更新日期:2019-11-14 00:00:00
abstract::New concepts in cell organization emerged in a medieval castle during a snowy week in January 2017 in the middle of the Austrian Alps. The occasion was the 10th Annaberg EMBO workshop in Goldegg am See; organized by Gabriele Seethaler, Catherine Rabouille and Marino Zerial. There were 95 participants, including many w...
journal_title:Journal of cell science
pub_type:
doi:10.1242/jcs.206219
更新日期:2017-07-15 00:00:00
abstract::Eukaryotic plasma membranes assemble actin filaments within seconds of activation of many receptors, especially during chemotaxis. Here, serum or sphingosine-1-phosphate stimulation of J774 and RAW macrophages released ADP within seconds into the extracellular medium, along with an adenylate kinase activity that conve...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.034207
更新日期:2009-02-15 00:00:00
abstract::SNARE (Soluble N-ethyl-maleimide sensitive factor Attachment protein Receptor) proteins assemble in tight core complexes, which promote fusion of carrier vesicles with target compartments. Members of this class of proteins are expressed in all eukaryotic cells and are distributed in distinct subcellular compartments. ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:2001-09-01 00:00:00
abstract::Pieces of small intestine from newborn, I- and 6-day-old piglets were incubated in vitro and ligated segments were incubated in vivo with polycationic ferritin (PCF) to determine the distribution and possible role in protein uptake of anionic sites on membranes at the luminal surfaces of the epithelial cells. Most PCF...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1980-12-01 00:00:00
abstract::We have investigated the intracellular distribution of insoluble fibronectin in HeLa tumour cells. By indirect immunofluorescence microscopy fibronectin was detected in the nuclear region, but not in the region of the cell surface. Isolated nuclei and isolated nuclear matrices also stained for fibronectin. By quantita...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1988-03-01 00:00:00
abstract::In previous work we have shown that ovarian hormones, when injected into ovariectomized rats, alter the fine structure of the plasma membrane of endometrial epithelial cells. In this paper freeze-fractures have been used to study the apical plasma membrane of endometrial epithelial cells of rats during the period of b...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1982-06-01 00:00:00
abstract::Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) triggers apoptosis selectively in tumor cells through interaction with TRAIL-R1/DR4 or TRAIL-R2/DR5 and this process is considered a promising avenue for cancer treatment. TRAIL resistance, however, is frequently encountered and hampers anti-cancer ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.109587
更新日期:2012-10-01 00:00:00
abstract::Nature Reviews Molecular Cell Biology Nature Publishing Group (2000). ISSN 1471-0072. Monthly First there was Annual Reviews, then came the monthly Elsevier Trends Journals, both of which try to identify hot topics in their chosen fields. The Current Opinion journals followed several years later, and Current Opinion i...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:2000-01-01 00:00:00
abstract::Meckel-Gruber syndrome (MKS) is a severe autosomal recessively inherited disorder caused by mutations in genes that encode components of the primary cilium and basal body. Here we show that two MKS proteins, MKS1 and meckelin, that are required for centrosome migration and ciliogenesis interact with actin-binding isof...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.043794
更新日期:2009-08-01 00:00:00
abstract::Parasite surfaces support multiple functions required for survival within their hosts, and maintenance and functionality of the surface depends on membrane trafficking. To understand the evolutionary history of trypanosomatid trafficking, where multiple lifestyles and mechanisms of host interactions are known, we exam...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.197640
更新日期:2017-04-15 00:00:00
abstract::Re-epithelialization of wounded skin is necessary for wound closure and restoration of barrier function and requires directional keratinocyte migration towards the center of the wound. The electric field (EF) generated immediately upon wounding could be the earliest signal keratinocytes receive to initiate directional...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.02330
更新日期:2005-05-01 00:00:00
abstract::The establishment of a tissue-culture system for epithelial cells derived from human foetal pancreas has recently been reported. Further analyses have now been made on these cells in vitro, together with parallel investigation of the distribution of different cell types within the intact foetal pancreas. Results suppo...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1988-05-01 00:00:00
abstract::Although telomere formation occurs through a different mechanism in Drosophila compared with other organisms, telomere associations result from mutations in homologous genes, indicating the involvement of similar pathways in chromosome end protection. We report here that mutations of the Drosophila melanogaster gene C...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.035097
更新日期:2009-03-15 00:00:00
abstract::We show in the present study that homologs of hsp90 and hsp70 are induced by heat shocks in Tetrahymena and appear to form a high molecular mass complex (approximately 700 kDa) with tubulin. Three members of the hsp70 family (hsp72, 73, and 78) and one member of the hsp90 family (hsp82) have been identified by immunol...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1997-07-01 00:00:00
abstract::Previously we cloned and characterized the hamster intermediate filament genes coding for vimentin and desmin. It was demonstrated that the cloned desmin gene was expressed after gene transfer and that the newly synthesized protein assembles into intermediate filaments. Here we present data on the transfection of modi...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1987-11-01 00:00:00
abstract::Hexabrachion is a large glycoprotein of the extracellular matrix (ECM) that is prominent in embryogenesis, wound healing and tumorigenesis. Because of the role of extracellular matrix proteins in the regulation of cell differentiation and migration, the interaction of hexabrachion with cells as well as with other comp...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1990-02-01 00:00:00
abstract::Cysteine proteases are involved in the degradation of intracellular and extracellular proteins, although their precise roles in vivo are not well understood. Here we characterise a genetic mutant of the Caenorhabditis elegans cathepsin L protease gene cpl-1. CPL-1 is provided maternally and is essential for C. elegans...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.01387
更新日期:2004-10-01 00:00:00
abstract::Host/symbiont specificity has been investigated in non-symbiotic and aposymbiotic brown and green hydra infected with various free-living and symbiotic species and strains of Chlorella and Chlorococcum. Morphology and ultrastructure of the symbioses obtained have been compared. Aposymbiotic Swiss Hydra viridis and Jap...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1986-12-01 00:00:00