Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2002-6-26
pubmed:abstractText
In order to investigate activation and internalization of c-kit we created a functional c-kit-EGFP chimera by inserting EYFP (enhanced yellow fluorescent protein) within the extracellular domain of c-kit immediately downstream of the signal sequence, SS-EYFP-kit. This location was chosen because the C-terminal fusion of EGFP to c-kit unexpectedly caused constitutive activation of the c-kit tyrosine kinase. As analysed in fixed cells and by real time imaging in vivo, SCF induced activation led to internalization of the fusion construct and translocation to punctate structures resembling vesicles. Analysis of the internalization process by time lapse imaging revealed high mobility and discontinuous movement of these vesicles and their predominantly radial tracks. Two subsets of vesicles were observed: Traffic of the majority of vesicles was directed from the periphery to the center of the cell and most likely represents the internalization of activated receptor molecules via the endosomal pathway. However, some vesicular structures were observed to move towards the periphery of the cell and probably contain newly synthesized protein to replace internalized receptor molecules. The calculated velocity of moving vesicles ranged from 0.05 to 0.2 microm per se. Vesicle formation upon SCF induced dimerization of the receptor was strictly dependent on kinase activity of c-kit. Treatment of cells with phenylarsine oxide, an agent blocking receptor internalization, prior to SCF stimulation resulted in abrogation of the translocation of the chimera to vesicles whereas accumulation of vesicles was observed when cells were treated with proteasome inhibitors. Cholesterol depletion of the cell membrane by methyl-beta-cyclodextrin resulted in dose dependent reduction of receptor internalization indicating that c-kit may be present in lipid rafts or that intact lipid rafts are required for efficient internalization of the receptor. Using the induction of vesicular structures as a sign of efficient internalization of the receptor analysis of mutant c-kit constructs deficient either in activation of PI3-Kinase or Src revealed that internalization of c-kit is dependent on recruitment of Src but not PI3-Kinase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Arsenicals, http://linkedlifedata.com/resource/pubmed/chemical/Cholesterol, http://linkedlifedata.com/resource/pubmed/chemical/Cyclodextrins, http://linkedlifedata.com/resource/pubmed/chemical/Cysteine Endopeptidases, http://linkedlifedata.com/resource/pubmed/chemical/Green Fluorescent Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Luminescent Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Multienzyme Complexes, http://linkedlifedata.com/resource/pubmed/chemical/Proteasome Endopeptidase Complex, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-kit, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Tyrosine, http://linkedlifedata.com/resource/pubmed/chemical/beta-Cyclodextrins, http://linkedlifedata.com/resource/pubmed/chemical/methyl-beta-cyclodextrin, http://linkedlifedata.com/resource/pubmed/chemical/oxophenylarsine
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4508-20
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:12085229-Animals, pubmed-meshheading:12085229-Arsenicals, pubmed-meshheading:12085229-Blotting, Western, pubmed-meshheading:12085229-COS Cells, pubmed-meshheading:12085229-Cell Line, pubmed-meshheading:12085229-Cholesterol, pubmed-meshheading:12085229-Cloning, Molecular, pubmed-meshheading:12085229-Cyclodextrins, pubmed-meshheading:12085229-Cysteine Endopeptidases, pubmed-meshheading:12085229-Dimerization, pubmed-meshheading:12085229-Endocytosis, pubmed-meshheading:12085229-Endosomes, pubmed-meshheading:12085229-Enzyme Activation, pubmed-meshheading:12085229-Flow Cytometry, pubmed-meshheading:12085229-Green Fluorescent Proteins, pubmed-meshheading:12085229-Luminescent Proteins, pubmed-meshheading:12085229-Membrane Microdomains, pubmed-meshheading:12085229-Microscopy, Fluorescence, pubmed-meshheading:12085229-Multienzyme Complexes, pubmed-meshheading:12085229-Proteasome Endopeptidase Complex, pubmed-meshheading:12085229-Protein Structure, Tertiary, pubmed-meshheading:12085229-Protein Transport, pubmed-meshheading:12085229-Proto-Oncogene Proteins c-kit, pubmed-meshheading:12085229-Recombinant Fusion Proteins, pubmed-meshheading:12085229-Time Factors, pubmed-meshheading:12085229-Tyrosine, pubmed-meshheading:12085229-beta-Cyclodextrins
pubmed:year
2002
pubmed:articleTitle
Analysing c-kit internalization using a functional c-kit-EGFP chimera containing the fluorochrome within the extracellular domain.
pubmed:affiliation
Department of Internal Medicine III, Laboratory of Leukemogenesis, Technical University of Munich, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't