Abstract:
:Activation of the epidermal growth factor receptor (EGFR) triggers multiple signaling pathways and rapid endocytosis of the epidermal growth factor (EGF)-receptor complexes. To directly visualize the compartmentalization of molecules involved in the major signaling cascade, activation of Ras GTPase, we constructed fusions of Grb2, Shc, H-Ras, and K-Ras with enhanced cyan fluorescent protein (CFP) or yellow fluorescent protein (YFP), and used live-cell fluorescence imaging microscopy combined with the fluorescence resonance energy transfer (FRET) technique. Stimulation of cells by EGF resulted in the accumulation of large pools of Grb2-CFP and YFP-Shc in endosomes, where these two adaptor proteins formed a complex with EGFR. H-Ras and K-Ras fusion proteins were found at the plasma membrane, particularly in ruffles and lamellipodia, and also in endosomes independently of GTP/GDP loading and EGF stimulation. The relative amount of endosomal H-Ras was higher than that of K-Ras, whereas K-Ras predominated at the plasma membrane. On application of EGF, Grb2, and Ras converge in the same endosomes through the fusion of endosomes containing either Grb2 or Ras or through the joint internalization of two proteins from the plasma membrane. To examine the localization of the GTP-bound form of Ras, we used a FRET assay that exploits the specific interaction of GTP-bound CFP-Ras with the YFP-fused Ras binding domain of c-Raf. FRET microscopy revealed that GTP-bound Ras is located at the plasma membrane, mainly in ruffles and at the cell edges, as well as in endosomes containing EGFR. These data point to the potential for endosomes to serve as sites of generation for persistent signaling through Ras.
journal_name
Mol Biol Celljournal_title
Molecular biology of the cellauthors
Jiang X,Sorkin Adoi
10.1091/mbc.01-11-0552keywords:
subject
Has Abstractpub_date
2002-05-01 00:00:00pages
1522-35issue
5eissn
1059-1524issn
1939-4586journal_volume
13pub_type
杂志文章abstract::Significant increase in JNK, c-Jun, and Cdk5 activities are reported in Alzheimer's disease (AD). Inhibition of c-Jun prevents neuronal cell death in in vivo AD models, highlighting it as a major JNK effector. Both JNK and Cdk5 promote neurodegeneration upon deregulation; however, Cdk5 has not been mechanistically lin...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e09-05-0433
更新日期:2009-11-01 00:00:00
abstract::The human fungal pathogen Candida albicans can switch between yeast, pseudohyphal, and hyphal morphologies. To investigate whether the distinctive characteristics of hyphae are due to increased activity of the Cdc42 GTPase, strains lacking negative regulators of Cdc42 were constructed. Unexpectedly, the deletion of th...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e06-05-0411
更新日期:2007-01-01 00:00:00
abstract::In the fission yeast Schizosaccharomyces pombe, three genes that function in the RNA interference (RNAi) pathway, ago1+, dcr1+, and rdp1+, have recently been shown to be important for timely formation of heterochromatin and accurate chromosome segregation. In the present study, we present evidence that null mutants fo...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e03-06-0433
更新日期:2004-03-01 00:00:00
abstract::We have addressed the question of whether or not Golgi fragmentation, as exemplified by that occurring during drug-induced microtubule depolymerization, is accompanied by the separation of Golgi subcompartments one from another. Scattering kinetics of Golgi subcompartments during microtubule disassembly and reassembly...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.9.1.191
更新日期:1998-01-01 00:00:00
abstract::Polalpha is the principal DNA polymerase for initiation of DNA replication and also functions in postinitiation DNA synthesis. In this study, we investigated the cell cycle responses induced by mutations in polalpha+. Germinating spores carrying either a deletion of polalpha+ (polalphaDelta) or a structurally intact b...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.9.8.2107
更新日期:1998-08-01 00:00:00
abstract::In kinetochores, the Ndc80 complex couples the energy in a depolymerizing microtubule to perform the work of moving chromosomes. The complex directly binds microtubules using an unstructured, positively charged N-terminal tail located on Hec1/Ndc80. Hec1/Ndc80 also contains a calponin homology domain (CHD) that increa...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E10-07-0626
更新日期:2011-04-15 00:00:00
abstract::A major regulatory function has been evidenced here for HSF1, the key transcription factor of the heat-shock response, in a large-scale remodeling of the cell epigenome. Indeed, upon heat shock, HSF1, in addition to its well-known transactivating activities, mediates a genome-wide and massive histone deacetylation. In...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e09-04-0295
更新日期:2009-12-01 00:00:00
abstract::Protein kinase C (PKC) zeta has been implicated in insulin-induced glucose uptake in skeletal muscle cell, although the underlying mechanism remains unknown. In this study, we investigated the effect of PKCzeta on actin remodeling and glucose transport in differentiated rat L6 muscle cells expressing myc-tagged glucos...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e05-10-0969
更新日期:2006-05-01 00:00:00
abstract::Two different human diseases, X-linked myotubular myopathy and Charcot-Marie-Tooth disease, result from mutant MTM1 or MTMR2 lipid phosphatases. Although events involved in endosomal PI(3)P and PI(3,5)P(2) synthesis are well established and pivotal in receptor signaling and degradation, enzymes involved in phosphoinos...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e08-04-0367
更新日期:2008-08-01 00:00:00
abstract::TPA-inducible sequence 11b/butyrate response factor 1 (TIS11b/BRF1) belongs to the tristetraprolin (TTP) family of zinc-finger proteins, which bind to mRNAs containing AU-rich elements in their 3'-untranslated region and target them for degradation. Regulation of TTP family function through phosphorylation by p38 MAP ...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E16-06-0379
更新日期:2016-12-01 00:00:00
abstract::DYF-1 is a highly conserved protein essential for ciliogenesis in several model organisms. In Caenorhabditis elegans, DYF-1 serves as an essential activator for an anterograde motor OSM-3 of intraflagellar transport (IFT), the ciliogenesis-required motility that mediates the transport of flagellar precursors and remov...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e10-03-0191
更新日期:2010-08-01 00:00:00
abstract::Cell invasion targets specific tissues in physiological placental implantation and pathological metastasis, which raises questions about how this process is controlled. We compare dermis and endometrium capacities to support trophoblast invasion, using matching sets of human primary fibroblasts in a coculture assay wi...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E13-03-0142
更新日期:2013-10-01 00:00:00
abstract::A genome-wide screen of 4168 homozygous diploid yeast deletion strains has been performed to identify nonessential genes that participate in the bipolar budding pattern. By examining bud scar patterns representing the sites of previous cell divisions, 127 mutants representing three different phenotypes were found: uni...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.12.7.2147
更新日期:2001-07-01 00:00:00
abstract::The Rab11 effector Rab11-family interacting protein 2 (Rab11-FIP2) regulates transcytosis through its interactions with Rab11a and myosin Vb. Previous studies implicated Rab11-FIP2 in the establishment of polarity in Madin-Darby canine kidney (MDCK) cells through phosphorylation of Ser-227 by MARK2. Here we examine th...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E11-08-0681
更新日期:2012-06-01 00:00:00
abstract::Bloom syndrome (BS) is a rare autosomal recessive disorder characterized by growth deficiency, immunodeficiency, genomic instability, and the early development of cancers of many types. BLM, the protein encoded by BLM, the gene mutated in BS, is localized in nuclear foci and absent from BS cells. BLM encodes a DNA hel...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.10.3.665
更新日期:1999-03-01 00:00:00
abstract::WDR92 is a highly conserved WD-repeat protein that has been proposed to be involved in apoptosis and also to be part of a prefoldin-like cochaperone complex. We found that WDR92 has a phylogenetic signature that is generally compatible with it playing a role in the assembly or function of specifically motile cilia. To...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E16-01-0040
更新日期:2016-04-15 00:00:00
abstract::Fibroblast growth factor (FGF) receptors (FGFRs) signal to modulate diverse cellular functions, including epithelial cell morphogenesis. In epithelial cells, E-cadherin plays a key role in cell-cell adhesion, and its function can be regulated through endocytic trafficking. In this study, we investigated the location, ...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e04-09-0845
更新日期:2005-01-01 00:00:00
abstract::Adaptins are subunits of adaptor protein (AP) complexes involved in the formation of intracellular transport vesicles and in the selection of cargo for incorporation into the vesicles. In this article, we report the results of a survey for adaptins from sequenced genomes including those of man, mouse, the fruit fly Dr...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.12.10.2907
更新日期:2001-10-01 00:00:00
abstract::Polarized assembly of actin filaments forms the basis of actin-based motility and is regulated both spatially and temporally. Cells use a variety of mechanisms by which intrinsically slower processes are accelerated, and faster ones decelerated, to match rates observed in vivo. Here we discuss how kinetic studies of i...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E15-06-0352
更新日期:2016-01-01 00:00:00
abstract::Sec1p/Munc18 (SM) family proteins regulate SNARE complex function in membrane fusion through their interactions with syntaxins. In addition to syntaxins, only a few SM protein interacting proteins are known and typically, their binding modes with SM proteins are poorly characterized. We previously identified Mso1p as ...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e09-07-0546
更新日期:2010-04-15 00:00:00
abstract::Platelet secretion is critical to hemostasis. Release of granular cargo is mediated by soluble NSF attachment protein receptors (SNAREs), but despite consensus on t-SNAREs usage, it is unclear which Vesicle Associated Membrane Protein (VAMPs: synaptobrevin/VAMP-2, cellubrevin/VAMP-3, TI-VAMP/VAMP-7, and endobrevin/VAM...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e06-09-0785
更新日期:2007-01-01 00:00:00
abstract::Normal epithelial cells undergo apoptosis when they are denied contact with the extracellular matrix, in a process termed "anoikis." Conversely, malignant epithelial cells typically acquire anchorage independence, i.e., the capacity to survive and grow in the absence of matrix interaction. Here we asked the question w...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.12.5.1519
更新日期:2001-05-01 00:00:00
abstract::Eukaryotic cell survival requires maintenance of plasma membrane (PM) homeostasis in response to environmental insults and changes in lipid metabolism. In yeast, a key regulator of PM homeostasis is target of rapamycin (TOR) complex 2 (TORC2), a multiprotein complex containing the evolutionarily conserved TOR protein ...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E18-10-0682
更新日期:2019-06-01 00:00:00
abstract::Transport of cellular and neuronal vesicles, organelles, and other particles along microtubules requires the molecular motor protein dynein (Mallik and Gross, 2004). Critical to dynein function is dynactin, a multiprotein complex commonly thought to be required for dynein attachment to membrane compartments (Karki and...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e06-08-0695
更新日期:2007-06-01 00:00:00
abstract::The beta 2 integrin lymphocyte function-associated antigen 1 (LFA-1) mediates activation-dependent adhesion of lymphocytes. To investigate whether lymphocyte-specific elements are essential for LFA-1 function, we expressed LFA-1 in the erythroleukemic cell line K562, which expresses only the integrin very late antigen...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.8.4.719
更新日期:1997-04-01 00:00:00
abstract::The concept of critical concentration (CC) is central to understanding the behavior of microtubules (MTs) and other cytoskeletal polymers. Traditionally, these polymers are understood to have one CC, measured in multiple ways and assumed to be the subunit concentration necessary for polymer assembly. However, this fra...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E19-02-0101
更新日期:2020-03-19 00:00:00
abstract::Vascular integrity and the maintenance of blood vessel continuity are fundamental features of the circulatory system maintained through endothelial cell-cell junctions. Defects in the endothelial barrier become an initiating factor in several pathologies, including ischemia/reperfusion, tumor angiogenesis, pulmonary e...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E13-12-0743
更新日期:2014-07-01 00:00:00
abstract::As the closest living relatives of animals, choanoflagellates offer unique insights into animal origins and core mechanisms underlying animal cell biology. However, unlike traditional model organisms, such as yeast, flies, and worms, choanoflagellates have been refractory to DNA delivery methods for expressing foreign...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E18-08-0514
更新日期:2018-12-01 00:00:00
abstract::Munc18-1 binds to syntaxin-1A via two distinct sites referred to as the "closed" conformation and N terminus binding. The latter has been shown to stimulate soluble N-ethylmaleimide-sensitive factor attachment protein receptor-mediated exocytosis, whereas the former is believed to be inhibitory or dispensable. To prec...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e09-08-0712
更新日期:2009-12-01 00:00:00
abstract::Human HT2-19 cells with a conditional cdk1 mutation stop dividing upon cdk1 inactivation and undergo multiple rounds of endoreplication. We show herein that major cell cycle events remain synchronized in these endoreplicating cells. DNA replication alternates with gap phases and cell cycle-specific cyclin E expression...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e02-12-0850
更新日期:2003-09-01 00:00:00