Linked Life Data

12356906

Source:http://linkedlifedata.com/resource/pubmed/id/12356906

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 21
pubmed:dateCreated
2002-10-1
pubmed:abstractText
The lipoprotein of insects, high-density lipophorin (HDLp), is homologous to that of mammalian low-density lipoprotein (LDL) with respect to its apolipoprotein structure. Moreover, an endocytic receptor for HDLp has been identified (insect lipophorin receptor, iLR) that is homologus to the LDL receptor. We transfected LDL-receptor-expressing CHO cells with iLR cDNA to study the endocytic uptake and intracellular pathways of LDL and HDLp simultaneously. Our studies provide evidence that these mammalian and insect lipoproteins follow distinct intracellular routes after receptor-mediated endocytosis. Multicolour imaging and immunofluorescence was used to visualize the intracellular trafficking of fluorescently labeled ligands in these cells. Upon internalization, which can be completely inhibited by human receptor-associated protein (RAP), mammalian and insect lipoproteins share endocytic vesicles. Subsequently, however, HDLp evacuates the LDL-containing endosomes. In contrast to LDL, which is completely degraded in lysosomes after dissociating from its receptor, both HDLp and iLR converge in a nonlysosomal juxtanuclear compartment. Colocalization studies with transferrin identified this organelle as the endocytic recycling compartment via which iron-depleted transferrin exits the cell. Fluorescently labeled RAP is also transported to this recycling organelle upon receptor-mediated endocytosis by iLR. Internalized HDLp eventually exits the cell via the recycling compartment, a process that can be blocked by monensin, and is re-secreted with a t(1/2) of approximately 13 minutes. From these observations, we conclude that HDLp is the first non-exchangeable apolipoprotein-containing lipoprotein that follows a transferrin-like recycling pathway despite the similarities between mammalian and insect lipoproteins and their receptors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
115
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4001-12
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:12356906-Animals, pubmed-meshheading:12356906-CHO Cells, pubmed-meshheading:12356906-Carrier Proteins, pubmed-meshheading:12356906-Cell Compartmentation, pubmed-meshheading:12356906-Cricetinae, pubmed-meshheading:12356906-Endocytosis, pubmed-meshheading:12356906-Endosomes, pubmed-meshheading:12356906-Fluorescent Antibody Technique, pubmed-meshheading:12356906-Humans, pubmed-meshheading:12356906-Insects, pubmed-meshheading:12356906-Ionophores, pubmed-meshheading:12356906-LDL-Receptor Related Protein-Associated Protein, pubmed-meshheading:12356906-Lipoproteins, pubmed-meshheading:12356906-Lipoproteins, LDL, pubmed-meshheading:12356906-Mammals, pubmed-meshheading:12356906-Monensin, pubmed-meshheading:12356906-Organelles, pubmed-meshheading:12356906-Protein Transport, pubmed-meshheading:12356906-Receptors, Cytoplasmic and Nuclear, pubmed-meshheading:12356906-Receptors, LDL, pubmed-meshheading:12356906-Transferrin, pubmed-meshheading:12356906-Transport Vesicles
pubmed:year
2002
pubmed:articleTitle
Insect lipoprotein follows a transferrin-like recycling pathway that is mediated by the insect LDL receptor homologue.
pubmed:affiliation
Department of Biochemical Physiology and Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. d.vanhoot@bio.uu.nl
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't