Abstract：
:Removal of the pro-domain of a cysteine protease is essential for activation of the enzyme. We have engineered a cysteine protease (CPB2.8) of the protozoan parasite Leishmania mexicana by site-directed mutagenesis to remove the active site cysteine (to produce CPB(C25G)). When CPB(C25G) was expressed in a L. mexicana mutant lacking all CPB genes, the inactive pro-enzyme was processed to the mature protein and trafficked to the lysosome. These results show that auto-activation is not required for correct processing of CPB in vivo. When CPB(C25G) was expressed in a L. mexicana mutant lacking both CPA and CPB genes, the majority of the pro-enzyme remained unprocessed and accumulated in the flagellar pocket. These data reveal that CPA can directly or indirectly process CPB(C25G) and suggest that cysteine proteases are targeted to lysosomes via the flagellar pocket. Moreover, they show that another protease can process CPB in the absence of either CPA or CPB, albeit less efficiently. Abolition of the glycosylation site in the mature domain of CPB did not affect enzyme processing, targeting or in vitro activity towards gelatin. This indicates that glycosylation is not required for trafficking. Together these findings provide evidence that the major route of trafficking of Leishmania cysteine proteases to lysosomes is via the flagellar pocket and therefore differs significantly from cysteine protease trafficking in mammalian cells.
journal_name
J Cell Scijournal_title
Journal of cell scienceauthors
Brooks DR,Tetley L,Coombs GH,Mottram JCkeywords:
subject
Has Abstractpub_date
2000-11-01 00:00:00pages
4035-41eissn
0021-9533issn
1477-9137journal_volume
113 ( Pt 22)pub_type
杂志文章abstract：:One of the hallmarks of cancer is the ability of tumor cells to invade surrounding tissues and metastasize. During metastasis, cancer cells degrade the extracellular matrix, which acts as a physical barrier, by developing specialized actin-rich membrane protrusion structures called invadopodia. The formation of invado...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.195552
更新日期：2017-03-15 00:00:00
abstract：:Electrical synapses (gap junctions) rapidly transmit signals between neurons and are composed of connexins. In neurons, connexin36 (Cx36) is the most abundant isoform; however, the mechanisms underlying formation of Cx36-containing electrical synapses are unknown. We focus on homocellular and heterocellular gap juncti...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.133066
更新日期：2014-03-15 00:00:00
abstract：:After DNA replication, cells condense their chromosomes in order to segregate them during mitosis. The condensation process as well as subsequent segregation requires phosphorylation of histone H3 at serine 10. Histone H3 phosphorylation initiates during G2 in pericentric foci prior to H3 phosphorylation in the chromo...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2001-02-01 00:00:00
abstract：:Chromatin is no longer considered to be a static structural framework for packaging DNA within the nucleus but is instead believed to be an interactive component of DNA metabolism. The ordered assembly of chromatin produces a nucleoprotein template capable of epigenetically regulating the expression and maintenance of...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：
更新日期：2000-08-01 00:00:00
abstract：:Tau is a neuronal microtubule-associated protein that appears to function in the formation and maintenance of axons by influencing microtubule organisation. Tau is a phosphoprotein and is more heavily phosphorylated in fetal than in adult brain, and is also hyperphosphorylated in Alzheimer's disease where it forms the...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1996-06-01 00:00:00
abstract：:NEDD8 is an important regulatory factor in many biological processes. However, the substrates for neddylation, and the relationship between the ubiquitin and NEDD8 pathways remain largely unknown. Here, we show that NEDD8 is covalently conjugated to histone 2A (H2A), and that neddylation of H2A antagonizes its ubiquit...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.138891
更新日期：2014-05-15 00:00:00
abstract：:Basement membranes are complex extracellular matrices contributing to the regulation of growth, migration and differentiation of many cell types. However, little is known about the mechanisms regulating the deposition and assembly of basement membrane from its constituents. We have investigated the role of extracellul...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1991-06-01 00:00:00
abstract：:Megalin is a receptor expressed by embryonic epithelia that mediates endocytosis of numerous ligands, including sonic hedgehog (Shh) and retinol, the precursor to retinoic acid (RA). The importance of Shh and RA signaling in neurodevelopment, combined with the fact that megalin-deficient mice show profound neurodevelo...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.00313
更新日期：2003-03-15 00:00:00
abstract：:Integrins are implicated in cell adhesion, migration and homeostasis. An important feature is their ability to adopt different affinity states that can be regulated by a variety of intra- and extracellular factors. To study affinity modulation of the integrin ectodomain by extracellular factors, we produced a soluble ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2001-04-01 00:00:00
abstract：:High-throughput neurotransmission at ribbon synapses of cochlear inner hair cells (IHCs) requires tight coupling of neurotransmitter release and balanced recycling of synaptic vesicles (SVs) as well as rapid restoration of release sites. Here, we examined the role of the adaptor protein AP180 (also known as SNAP91) fo...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.236737
更新日期：2020-01-22 00:00:00
abstract：:Immunofluorescent anti-tubulin staining has been used to follow nuclear progression from dictyate to metaphase II during meiotic maturation of mouse oocytes in vitro. Antibody directed against tubulin isolated from sea-urchin eggs decorates the metaphase I and metaphase II spindles, as well as the cytoplasmic bridge, ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1978-02-01 00:00:00
abstract：:A polyclonal antibody was raised to the C-terminal region of fission yeast BiP. The use of this antibody for immunoprecipitation, western blotting and immunofluorescence has confirmed and extended the observations made previously with an epitope-tagged BiP molecule. A fraction of BiP protein is glycosylated in Schizos...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1993-08-01 00:00:00
abstract：:We have generated novel lentiviral vectors to integrate various connexin cDNAs into primary, non-dividing cells. We have used these vectors to test whether proper control of insulin secretion depends on a specific connexin isoform and/or on its level of expression. We have observed that transduced connexin32, connexin...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.00442
更新日期：2003-06-01 00:00:00
abstract：:The E-cadherin-catenin complex regulates Ca(2+)-dependent cell-cell adhesion and is localized to the basolateral membrane of polarized epithelial cells. Uncoupling beta-catenin from E-cadherin by deletion or substitution mutations causes accumulation of these proteins in intracellular compartments, including the trans...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.03489
更新日期：2007-12-15 00:00:00
abstract：:Calmodulin was localized in the small intestine of Necturus maculosa at both the light- and electron-microscopic levels utilizing an affinity-purified, monospecific antibody and immunoperoxidase cytochemistry. The microvilli and basolateral membranes of the epithelium were highly reactive, the cytoplasm was moderately...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1988-12-01 00:00:00
abstract：:Exocytotic incorporation of plasmalemmal precursor vesicles (PPVs) into the cell surface is necessary for axonal outgrowth and is known to occur mainly at the nerve growth cone. We have demonstrated recently that plasmalemmal expansion is regulated at the growth cone by IGF-1, but not by BDNF, in a manner that is quas...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.02490
更新日期：2005-08-15 00:00:00
abstract：:Tissues fixed in osmium tetroxide or in combined osmium and glutaraldehyde (Hinde), embedded in Spurr's medium, cut at 0-5-I mum and mounted in Farrants' gum medium containing ethyl gallate, show good staining of lipid-contaning structures (droplets of triglyceride, membranes, mitochondria, etc.) in the light microsco...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1975-12-01 00:00:00
abstract：:Splice variants of certain genes impact on genetic biodiversity in mammals. The tumor suppressor TP53 gene (encoding p53) plays an important role in the regulation of tumorigenesis in hepatocellular carcinoma (HCC). Δ40p53α is a naturally occurring p53 isoform that lacks the N-terminal transactivation domain, yet litt...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.190736
更新日期：2017-02-01 00:00:00
abstract：:DNA replication in eukaryotic cells initiates from multiple replication origins that are distributed throughout the genome. Coordinating the usage of these origins is crucial to ensure complete and timely replication of the entire genome precisely once in each cell cycle. Replication origins fire according to a cell-t...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.096701
更新日期：2013-03-15 00:00:00
abstract：:The role of inhibition of prelamin A processing in the inhibition of DNA synthesis by lovastatin was examined by expressing prelamin A in F9 teratocarcinoma cells. These cells, normally lacking expression of the A/C lamins, were transfected with constructs expressing either prelamin A or mature lamin A and the effect ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1994-08-01 00:00:00
abstract：:If mitotic-arrested, cold-stored HeLa cells are incubated at 37 degrees C a proportion of the population divides by an aberrant process which we have called subdivision by extrusion. This process has been studied by time-lapse photography and shown to differ from normal cleavage in several respects. The cell surface b...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1976-11-01 00:00:00
abstract：:Rac1 is a small Rho family GTPase that regulates changes in cell morphology associated with cell spreading and migration. Integrin-mediated adhesion is known to activate Rac1 and to regulate the interaction of Rac1 with downstream effectors. Currently, it is not clear how integrins signal Rac1 activation following cel...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.00109
更新日期：2002-11-15 00:00:00
abstract：:To understand the molecular mechanisms underlying sorting of apical and basolateral membrane components in human intestinal epithelial cells, we have cloned the human homolog of rat syntaxin 3 and looked for its subcellular localization. Endogenous human syntaxin 3 was found to be localized at the apical membrane of c...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1997-09-01 00:00:00
abstract：:Increases in cytosolic Ca(2+) concentration ([Ca(2+)](c)) mediated by inositol (1,4,5)-trisphosphate [Ins(1,4,5)P(3), hereafter InsP(3)] regulate activities that include division, contraction and cell death. InsP(3)-evoked Ca(2+) release often begins at a single site, then regeneratively propagates through the cell as...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.105163
更新日期：2012-11-15 00:00:00
abstract：:We previously demonstrated that activation of v-ABL protein tyrosine kinase resulted in suppression of apoptosis following interleukin-3 removal using an interleukin-3-dependent haemopoietic cell line transfected with a temperature-sensitive mutant of the v-abl oncoprotein (IC.DP). Cellular signalling events associate...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1995-07-01 00:00:00
abstract：:Epithelia are compact tissues comprising juxtaposed cells that function as mechanical and chemical barriers between the body and the environment. This barrier relies, in part, on adhesive contacts within adherens junctions, which are formed and stabilized by E-cadherin and catenin proteins linked to the actomyosin cyt...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.151472
更新日期：2014-12-15 00:00:00
abstract：:Filamin (actin-binding protein) is a cytoskeletal protein that crosslinks actin filaments in vitro. Filamin is thought to be involved in a variety of cell types in stabilizing actin networks, and in platelets it may play a role in linking actin to the membrane. In this report, we describe a monoclonal antibody (Mab 6E...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1989-09-01 00:00:00
abstract：:In Rat-1 fibroblasts, v-Src causes a profound remodelling of cortical actin cytoskeleton. This transformation includes membrane ruffling, a hallmark of the leading edge in migrating cells, and results from activation of phosphoinositide 3-kinase (PI 3-kinase), phospholipase C (PLC) and phospholipase D (PLD). We theref...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.01359
更新日期：2004-09-15 00:00:00
abstract：:The human Ras superfamily of small GTPases controls essential cellular processes such as gene expression and cell proliferation. As their deregulation is widely associated with human cancer, small GTPases and their regulatory proteins have become increasingly attractive for the development of novel therapeutics. Class...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.210419
更新日期：2018-01-08 00:00:00
abstract：:Polyethylene glycol (PEG) was used to fuse trout sperm with Chinese hamster fibroblasts (CHW-1102). As judged by light microscopy, PEG significantly increased the number of associations between the two cell types. Electron microscopy revealed that the sperm nuclei were in the cytoplasm of CHW-1102 in cultures that had...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1982-02-01 00:00:00
