Abstract:
:An essential step in mammalian fertilisation is the sperm acrosome reaction (AR) - exocytosis of a single large vesicle (the acrosome) that surrounds the nucleus at the apical sperm head. The acrosomal and plasma membranes fuse, resulting in both the release of factors that might facilitate penetration of the zona pellucida (which invests the egg) and the externalisation of membrane components required for gamete fusion. Exocytosis in somatic cells is a rapid process - typically complete within milliseconds - yet acrosomal enzymes are required throughout zona penetration - a period of minutes. Here, we present the first studies of this crucial and complex event occurring in real-time in individual live sperm using time-lapse fluorescence microscopy. Simultaneous imaging of separate probes for acrosomal content and inner acrosomal membrane show that rapid membrane fusion, initiated at the cell apex, is followed by exceptionally slow dispersal of acrosomal content (up to 12 minutes). Cells that lose their acrosome prematurely (spontaneous AR), compromising their ability to penetrate the egg vestments, are those that are already subject to a loss of motility and viability. Cells undergoing stimulus-induced AR (progesterone or A23187) remain viable, with a proportion remaining motile (progesterone). These findings suggest that the AR is a highly adapted form of exocytosis.
journal_name
J Cell Scijournal_title
Journal of cell scienceauthors
Harper CV,Cummerson JA,White MR,Publicover SJ,Johnson PMdoi
10.1242/jcs.030379subject
Has Abstractpub_date
2008-07-01 00:00:00pages
2130-5issue
Pt 13eissn
0021-9533issn
1477-9137pii
jcs.030379journal_volume
121pub_type
杂志文章abstract::Separation of clathrin-coated pits from the plasma membrane, a key event during endocytosis, is thought to be driven by dynamin and the actin cytoskeleton. However, the mechanism for the actin-mediated endocytosis remains elusive. RNA interference-mediated suppression of cortactin, an F-actin binding protein that prom...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.01668
更新日期:2005-02-15 00:00:00
abstract::The asparaginyl hydroxylase factor inhibiting HIF-1 (FIH-1) is an important suppressor of hypoxia-inducible factor (HIF) activity. In addition to HIF-α, FIH-1 was previously shown to hydroxylate other substrates within a highly conserved protein interaction domain, termed the ankyrin repeat domain (ARD). However, to d...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.117564
更新日期:2013-06-15 00:00:00
abstract::A Mr 60,000 protein of the axonal cortical cytoplasm, which is recognized by a novel monoclonal antibody, is described. The antibody, DR1, was produced by immunizing mice with a soluble extract of bovine brain membranes that is enriched in known membrane cytoskeletal proteins. DR1 recognizes a Mr 60,000 protein in thi...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1989-11-01 00:00:00
abstract::Previous investigators have examined mitochondrial DNA (mtDNA) in the electron microscope (EM) after extraction from mitochondria and rotary shadowing. We have observed mtDNA in situ by the osmiumammine procedure for specific staining of DNA in the EM. The procedure was modified to improve the regularity of the staini...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1992-04-01 00:00:00
abstract::Fluorescence illumination can cause phototoxicity that negatively affects living samples. This study demonstrates that much of the phototoxicity and photobleaching experienced with live-cell fluorescence imaging occurs as a result of 'illumination overhead' (IO). This occurs when a sample is illuminated but fluorescen...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.242834
更新日期:2020-02-21 00:00:00
abstract::Sustained neurotransmission requires the tight coupling of synaptic vesicle (SV) exocytosis and endocytosis. The mechanisms underlying this coupling are poorly understood. We tested the hypothesis that a cGMP-dependent protein kinase (PKG), encoded by the foraging (for) gene in Drosophila melanogaster, is critical for...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.227165
更新日期:2019-04-05 00:00:00
abstract::Nearly all intermediate filament (IF) proteins share two sequence motifs located at the N- and the C-terminal ends of their helical rod domain ('coil 1a' and 'coil 2b', respectively). To examine the structural role of the coil 2b motif, we have performed in vitro assembly studies and in vivo microinjection experiments...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1992-05-01 00:00:00
abstract::The formation of cytoplasmic stress granules and the innate immune response are two distinct cellular stress responses. Our study investigated the involvement of four innate immune proteins - retinoic-acid-inducible gene I (RIG-I, also known as DDX58), melanoma differentiation-associated gene 5 (MDA5, also known as IF...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.139626
更新日期:2014-06-01 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::The process of cell migration is initiated by protrusion at the leading edge of the cell, the formation of peripheral adhesions, the exertion of force on these adhesions, and finally the release of the adhesions at the rear of the cell. Focal adhesion kinase (FAK) is intimately involved in the regulation of this proce...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.02380
更新日期:2005-06-15 00:00:00
abstract::Prox1 plays pivotal roles during embryonic lymphatic development and maintenance of adult lymphatic systems by modulating the expression of various lymphatic endothelial cell (LEC) markers, such as vascular endothelial growth factor receptor 3 (VEGFR3). However, the molecular mechanisms by which Prox1 transactivates i...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.083998
更新日期:2011-08-15 00:00:00
abstract::A number of epithelia form tubulocysts in vitro when overlaid with type I collagen gel. Because collagen receptors are generally believed to be expressed on the basolateral domain, the mechanism by which collagen elicits this morphogenetic response from the apical surface is unclear. To investigate the role of beta 1 ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1996-07-01 00:00:00
abstract::In 1993, a Commentary in this journal described how a simple mechanical model of cell structure based on tensegrity architecture can help to explain how cell shape, movement and cytoskeletal mechanics are controlled, as well as how cells sense and respond to mechanical forces (J. Cell Sci. 104, 613-627). The cellular ...
journal_title:Journal of cell science
pub_type: 杂志文章,评审
doi:10.1242/jcs.00359
更新日期:2003-04-01 00:00:00
abstract::PINCH1 is composed of 5 LIM domains, binds integrin-linked kinase (ILK) and locates to integrin-mediated adhesion sites. In order to investigate PINCH1 function we generated mice and embryonic stem (ES) cell-derived embryoid bodies (EBs) lacking the PINCH1 gene. Similar to mice lacking beta1 integrin or Ilk, loss of P...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.02422
更新日期:2005-07-01 00:00:00
abstract::In situ observations of the development of hippocampal and cortical neurons indicate that final axon-dendrite identity is defined at the time of generation of the first two, oppositely positioned, neurites. Quite differently, in vitro studies demonstrated that axonal fate is defined by the stochastic selection of one ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.023143
更新日期:2008-01-15 00:00:00
abstract::To optimally perform the diversity of metabolic functions that occur within peroxisomes, cells must dynamically regulate peroxisome size, number and content in response to the cell state and the environment. Except for transcriptional regulation little is known about the mechanisms used to perform this complicated fea...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.195255
更新日期:2016-11-01 00:00:00
abstract::Activator of G-protein signaling 3 (AGS3, also known as GPSM1) regulates the trans-Golgi network. The AGS3 GoLoco motif binds to Gαi and thereby regulates the transport of proteins to the plasma membrane. Compaction of early embryos is based on the accumulation of E-cadherin (Cdh1) at cell-contacted membranes. However...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.243238
更新日期:2020-12-07 00:00:00
abstract::Hepatocyte growth factor (HGF)/scatter factor modulates the motility of HT29 colon carcinoma cells in vitro by inducing morphological changes that depend on the type of extra-cellular matrix (ECM) ligand; HGF-induced scattering of HT29 cells is observed if cells are grown on plastic coated with serum proteins but not ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1998-04-01 00:00:00
abstract::Start is the main decision point in the eukaryotic cell cycle at which cells commit to a new round of cell division. It involves the irreversible activation of a transcriptional programme through the inactivation of Start transcriptional repressors: the retinoblastoma family in mammals, or Whi5 and its recently identi...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.251413
更新日期:2020-12-21 00:00:00
abstract::MOR1, the Arabidopsis thaliana homologue of the Xenopus microtubule-associated protein MAP215, is required for spatial organization of the acentrosomal microtubule arrays of plant cells. To determine how loss of MOR1 function affects microtubule dynamics, we compared various parameters of microtubule dynamics in the t...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.039065
更新日期:2008-12-15 00:00:00
abstract::Phosphoinositides regulate numerous processes in various subcellular compartments. Whereas many stimuli trigger changes in the plasma-membrane PtdIns(4,5)P(2) concentration, little is known about its precursor, PtdIns(4)P, in particular whether there are stimulus-induced alterations independent of those of PtdIns(4,5)...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.060525
更新日期:2010-05-01 00:00:00
abstract::Human breast cancer cell lines, as well as transformed mammary epithelial cells (HBL-100) and growth-stimulated normal breast epithelial cells showed positive cytochemical reaction with the proteinase substrate 2-(N-benzyloxycarbonyl-L-arginyl-L-arginylamido)-4-methoxynapht halene, in the presence of 5-nitrosalicylald...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1987-02-01 00:00:00
abstract::In this paper we examine DNA repair in the mouse. Using stringently applied inhibitors of DNA synthesis (hydroxyurea and 1-beta-D-arabinofuranosylcytosine) after ultraviolet irradiation we have quantitated an early step in the repair process - the frequency of single-strand DNA breaks, products of enzymic incision--in...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1983-03-01 00:00:00
abstract::Although it is well established that embryonic stem (ES) cells have the potential to differentiate into dopamine neurons, the molecular basis of this process, particularly the role of microRNAs (miRNAs), remains largely unknown. Here we report that miR-132 plays a key role in the differentiation of dopamine neurons by...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.086421
更新日期:2012-04-01 00:00:00
abstract::The mechanisms by which volatile general anaesthetics (VAs) produce a depression of central nervous system are beginning to be better understood, but little is known about a number of side effects. Here, we show that the cold receptor transient receptor potential melastatin 8 (TRPM8) undergoes a complex modulation by ...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.131631
更新日期:2013-10-01 00:00:00
abstract::Cellular activities are regulated by environmental stimuli through protein phosphorylation. Target of rapamycin (TOR), a serine/threonine kinase, plays pivotal roles in cell proliferation and cell growth in response to nutrient status. In Schizosaccharomyces pombe, TORC1, which contains Tor2, plays crucial roles in nu...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.060319
更新日期:2010-03-01 00:00:00
abstract::Mutations in leucine-rich repeat kinase 2 (LRRK2) are associated with Parkinson’s disease, but the precise physiological function of the protein remains ill-defined. Recently, our group proposed a model in which LRRK2 kinase activity is part of an EndoA phosphorylation cycle that facilitates efficient vesicle formatio...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.158196
更新日期:2015-02-01 00:00:00
abstract::Actin-based myosin motors have a pivotal role in intracellular trafficking in eukaryotic cells. The parasitic protozoan organism Leishmania expresses a novel class of myosin, myosin XXI (Myo21), which is preferentially localized at the proximal region of the flagellum. However, its function in this organism remains la...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.064725
更新日期:2010-06-15 00:00:00
abstract::In Saccharomyces cerevisiae, DNA replication stress activates the replication checkpoint, which slows S-phase progression, stabilizes slowed or stalled replication forks, and relieves inhibition of the ribonucleotide reductase (RNR) complex. To identify novel genes that promote cellular viability after replication str...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.03221
更新日期:2006-12-15 00:00:00
abstract::During spermatogenesis in mammals, the transcripts of transition protein 1 (TP 1) and protamine 1 (Prm 1) are under translational regulation. Following their transcription in round spermatids, the mRNAs for TP 1 and Prm 1 are stored in the cytoplasm from 3-7 days before being translated towards the end of spermatogene...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1991-09-01 00:00:00