Abstract：
:An acrosome reaction was induced in ejaculated ram spermatozoa by treatment with calcium and the ionophore A23187. Samples were fixed at different times after initiation of induction, and the morphological changes within the head membranes that took place as exocytosis occurred were studied in freeze-fracture replicas. Reacted acrosomes appeared in individual spermatozoa within the calcium/ionophore-treated population at different times after the start of treatment; the first cells had reacted by 10 min, whereas some took more than 40 min to react. No changes were observed in control populations. An early effect of treatment (seen in most cells within 10 min) was the appearance of particle-free 'clearings' in the plasma membrane over the entire acrosomal region, with aggregation of intramembranous particles between and around these 'clearings'. At the same time, there was an increase in the number of large particles (greater than or equal to 10 nm) within the plasma membrane over the 'lunula' of the equatorial segment and the anterior part of the post-acrosomal region. Fusion of the plasma and outer acrosomal membranes began in a limited area at the border between the anterior and equatorial segments of the acrosome. It then spread, following arborescent pathways, sideways along this border and forwards towards the apex of the head. This labyrinthic propagation resulted in an 'acrosomal cap' increasingly fenestrated towards its posterior margin. Fusion propagation over the equatorial segment was inhibited, apparently as a result of the highly ordered structure of the membranes in this region.
journal_name
J Cell Scijournal_title
Journal of cell scienceauthors
Fléchon JE,Harrison RA,Fléchon B,Escaig Jsubject
Has Abstractpub_date
1986-03-01 00:00:00pages
43-63eissn
0021-9533issn
1477-9137journal_volume
81pub_type
杂志文章abstract：:The plasma membrane Ca2+-ATPase-2 (PMCA2) is expressed in stereocilia of hair cells of the inner ear, whereas PMCA1 is expressed in the basolateral plasma membrane of hair cells. Both extrude excess Ca2+ from the cytosol. They are predicted to contain ten membrane-spanning segments, two large cytoplasmic loops as well...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.03030
更新日期：2006-07-15 00:00:00
abstract：:The distribution of centromeres in the interphase nuclei of human diploid fibroblasts was analyzed using anti-centromere immunofluorescence and laser scanning confocal microscopoy. The positions of the centromeres were placed within the nuclear chromatin distribution and presented some aspects of the dynamics of nucle...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1991-06-01 00:00:00
abstract：:Developing oral organelles of dividing Tetrahymena corlissi appear to be positioned by mechanisms which assess distances as a proportion of the organism's overall dimensions. In some respects, the cortex of this protozoan obeys the 'French flag' rule formulated by Wolpert for describing regulation of spatial proportio...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1976-06-01 00:00:00
abstract：:During mouse meiosis, the early prophase RAD51/DMC1 recombination protein sites, which are associated with the chromosome cores and which serve as markers for ongoing DNA-DNA interactions, are in ten-fold excess of the eventual reciprocal recombinant events. Most, if not all, of these early interactions are eliminated...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2002-04-15 00:00:00
abstract：:Deubiquitylating (or deubiquitinating) enzymes (DUBs) are proteases that reverse protein ubiquitylation and therefore modulate the outcome of this post-translational modification. DUBs regulate a variety of intracellular processes, including protein turnover, signalling pathways and the DNA damage response. They have ...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.201855
更新日期：2017-06-15 00:00:00
abstract：:Hormone secretion by pituitary cells is decreased by roscovitine, an inhibitor of cyclin-dependent kinase 5 (Cdk5). Roscovitine treatment reorganizes cortical actin and ultrastructural analysis demonstrates that roscovitine limits the ability of secretory granules to approach the plasma membrane or one another. Trio, ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.01333
更新日期：2004-09-15 00:00:00
abstract：:We investigated the relative contributions of phagocytosis and plasma membrane transport to the uptake of amino acids and a protein (egg albumin) in amounts which allow Tetrahymena thermophila to grow and multiply. We used a mutant capable of indefinite growth without food vacuole formation (phagocytosis) and its wild...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1979-04-01 00:00:00
abstract：:In the fission yeast Schizosaccharomyces pombe, the protein kinase Chk1 has an essential role in transducing a delay signal to the cell cycle machinery in the presence of DNA damage. Fission yeast cells lacking the chk1 gene do not delay progression of the cell cycle in response to damage and are thus sensitive to DNA...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.00133
更新日期：2002-12-01 00:00:00
abstract：:Cell migration is a complex process requiring density and rigidity sensing of the microenvironment to adapt cell migratory speed through focal adhesion and actin cytoskeleton regulation. ICAP-1 (also known as ITGB1BP1), a β1 integrin partner, is essential for ensuring integrin activation cycle and focal adhesion forma...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.200139
更新日期：2017-02-01 00:00:00
abstract：:Small latent TGF-beta consists of latency associated peptide (LAP) bound to the 25 kDa TGF-beta by noncovalent interactions. Small latent TGF-beta is secreted from cells and deposited into the extracellular matrix as covalent complexes with its binding proteins, LTBPs. Four LTBPs have been molecularly cloned and their...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2001-08-01 00:00:00
abstract：:In trypanosomes, the flagellum is rooted in the flagellar pocket, a surface micro-domain that is the sole site for endocytosis and exocytosis. By analysis of anterograde or retrograde intraflagellar transport in IFT88RNAi or IFT140RNAi mutant cells, we show that elongation of the new flagellum is not required for flag...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.035626
更新日期：2008-11-15 00:00:00
abstract：:The pericentriolar recycling endosome (RE) may be an alternative compartment through which some beta2-adrenergic receptors (beta2ARs) recycle from early endosomes to the cell surface during prolonged exposure to agonist. For the transferrin receptor, CXCR2, and the M4-muscarinic acetylcholine receptor, trafficking thr...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.01168
更新日期：2004-07-01 00:00:00
abstract：:We have investigated the effect of nitric oxide (NO) on apoptosis in Swiss 3T3 fibroblasts and compared it to the effect of the nitrosonium cation (NO+). Both species induced apoptosis, confirmed by electron microscopy, propidium iodide staining, DNA laddering and activation of caspases. The kinetics of triggering apo...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1997-09-01 00:00:00
abstract：:Yeast Reb1 and its mammalian ortholog TTF1 are conserved Myb-type DNA-binding proteins that bind to specific sites near the 3'-end of rRNA genes (rDNA). Here, they participate in the termination of transcription driven by RNA polymerase I and block DNA replication forks approaching in the opposite direction. We found ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.070987
更新日期：2011-01-01 00:00:00
abstract：:The karyo-cytoskeleton of cells cultured in vitro was investigated employing resinless section immunogold electron microscopy. Cells were entrapped in low-melting agarose, sequentially extracted with various buffers and digested with nucleases to obtain karyo-cytoskeletal frameworks and reacted with specific primary a...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1991-01-01 00:00:00
abstract：:The current paradigm of noncanonical NF-κB signaling suggests that the loss of TRAF2, TRAF3 or cIAP1 and cIAP2 leads to stabilization of NF-κB-inducing kinase (NIK) to activate the noncanonical pathway. Although a crucial role of RIP1 in the TNFα-induced canonical NF-κB pathway has been well established, its involveme...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.075770
更新日期：2011-02-15 00:00:00
abstract：:Eukaryotic cell cycles are controlled by the activities of cyclin-dependent kinases (cdks). The major cdk in budding yeast, Saccharomyces cerevisiae, is Cdc28p. Activation of Cdc28p requires phosphorylation on threonine 169 and binding to a cyclin. Thr-169 is phosphorylated by the cdk-activating kinase (CAK), Cak1p, w...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1998-12-18 00:00:00
abstract：:The invasiveness of mouse lymphocytes and thymocytes, rabbit peritoneal neutrophil granulocytes (PMNs), mouse peritoneal macrophages (both activated and non-activated) and pig endothelial cells was assayed by implanting these cells to the chick wing bud. Cells of each type moved into the wing mesenchyme, although acti...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1979-12-01 00:00:00
abstract：:By differential screening of a Xenopus laevis egg cDNA library, we have isolated a 2,111 bp cDNA which corresponds to a maternal mRNA specifically deadenylated after fertilisation. This cDNA, called Eg2, encodes a 407 amino acid protein kinase. The pEg2 sequence shows significant identity with members of a new protein...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1998-03-01 00:00:00
abstract：:The structure of a late endosomal compartment, which contains the bulk of the cation-independent mannose 6-phosphate receptor (MPR) in NRK cells, is documented using immunocytochemistry and cryo-sections, as well as conventional Epon sections. This compartment, which we refer to as the prelysosomal compartment (PLC), ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
abstract：:Using a reconstituted complex of profilin and skeletal muscle actin as an antigen, we generated a monoclonal mouse antibody against actin, termed 2G2. As revealed by immunoblots of proteolytic actin fragments and by pepscan analysis, the antibody recognises a nonsequential epitope on actin which is located within thre...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1999-03-01 00:00:00
abstract：:CDC6, a replication licensing protein, is partially exported to the cytoplasm in human cells through phosphorylation by Cdk during S phase, but a significant proportion remains in the nucleus. We report here that human CDC6 physically interacts with ATR, a crucial checkpoint kinase, in a manner that is stimulated by p...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.058693
更新日期：2010-01-15 00:00:00
abstract：:Prion diseases are fatal neurodegenerative diseases characterised by the accumulation of misfolded prion protein (PrP(Sc)) in the brain. They are caused by the templated misfolding of normal cellular protein, PrP(C), by PrP(Sc). We have recently generated a unique cell system in which epitope-tagged PrP(C) competent t...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.120477
更新日期：2013-08-15 00:00:00
abstract：:Eukaryogenesis - the emergence of eukaryotic cells - represents a pivotal evolutionary event. With a fundamentally more complex cellular plan compared to prokaryotes, eukaryotes are major contributors to most aspects of life on Earth. For decades, we have understood that eukaryotic origins lie within both the Archaea ...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.178566
更新日期：2016-10-15 00:00:00
abstract：:Inactivation of the transcription factor and tumor suppressor p53, and overexpression or mutational activation of PIK3CA, which encodes the p110alpha catalytic subunit of phosphatidylinositol-3-kinase (PI3K), are two of the most common deleterious genomic changes in cancer, including in ovarian carcinomas. We investig...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.013029
更新日期：2008-03-01 00:00:00
abstract：:The tachyzoite stage of the protozoan parasite Toxoplasma gondii has two populations of microtubules: spindle microtubules and subpellicular microtubules. To determine how these two microtubule populations are regulated, we investigated microtubule behavior during the cell cycle following treatment with microtubule-di...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2002-03-01 00:00:00
abstract：:A transformed variant derived as a clone from normal 3T3 cells infected with simian virus 40 (SV40) has been found to possess a phenotype intermediate between that of normal cells and that characteristic of the transformed state, yet cells of the variant still test positively for the SV40-specific nuclear T-antigen. T...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1975-08-01 00:00:00
abstract：:MicroRNAs are short non-coding RNAs involved in post-transcriptional regulation of multiple messenger RNA targets. The miR-1/miR-206 family is expressed during skeletal muscle differentiation and is an integral component of myogenesis. To better understand miR-1/miR-206 function during myoblast differentiation we iden...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.101758
更新日期：2012-08-01 00:00:00
abstract：:Integrin-mediated cell adhesion is central to cell survival, differentiation and motility. Many cell responses induced by integrins require both receptor occupancy and receptor aggregation, and appear to be regulated by both biochemical and biophysical means. Multidomain extracellular matrix molecules may serve to fos...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2002-04-01 00:00:00
abstract：:Oncogenic forms of the non-receptor tyrosine kinase Src alter cell structure, in particular the actin cytoskeleton and the adhesion networks that control cell migration, and also transmit signals that regulate proliferation and cell survival. Recent work indicates that they do so by influencing the RhoA-ROCK pathway t...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.01111
更新日期：2004-03-01 00:00:00
