Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2004-10-15
pubmed:abstractText
Recent findings suggest that Delta/Serrate/Lag2 (DSL) signals activate Notch by an unprecedented mechanism that requires the ligands to be endocytosed in signal-sending cells to activate the receptor in signal-receiving cells. Here, we show that cells devoid of Epsin, a conserved adaptor protein for Clathrin-mediated endocytosis, behave normally except that they cannot send DSL signals. Surprisingly, we find that Epsin is not required for bulk endocytosis of DSL proteins. Instead, Epsin appears to be essential for targeting DSL proteins to a special endocytic pathway that they must enter to acquire signaling activity. We present evidence that DSL proteins must be mono-ubiquitinated to be targeted by Epsin to this pathway. Furthermore, we show that the requirements for both Epsin and mono-ubiquitination can be bypassed by introducing the internalization signal that mediates endocytosis and recycling of the Low Density Lipoprotein (LDL) receptor. We propose that Epsin is essential for DSL signaling because it targets mono-ubiquitinated DSL proteins to an endocytic recycling compartment that they must enter to be converted into active ligands. Alternatively Epsin may be required to target mono-ubiquitinated DSL proteins to a particular subclass of coated pits that have special properties essential for Notch activation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adaptor Proteins, Vesicular..., http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Cholesterol, LDL, http://linkedlifedata.com/resource/pubmed/chemical/Drosophila Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Hedgehog Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Intercellular Signaling Peptides..., http://linkedlifedata.com/resource/pubmed/chemical/Intracellular Signaling Peptides..., http://linkedlifedata.com/resource/pubmed/chemical/Ligands, http://linkedlifedata.com/resource/pubmed/chemical/Lqf protein, Drosophila, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Notch, http://linkedlifedata.com/resource/pubmed/chemical/Serrate proteins, http://linkedlifedata.com/resource/pubmed/chemical/Ubiquitin, http://linkedlifedata.com/resource/pubmed/chemical/Vesicular Transport Proteins, http://linkedlifedata.com/resource/pubmed/chemical/delta protein, http://linkedlifedata.com/resource/pubmed/chemical/epsin, http://linkedlifedata.com/resource/pubmed/chemical/hedgehog protein, Drosophila, http://linkedlifedata.com/resource/pubmed/chemical/notch protein, Drosophila
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0950-1991
pubmed:author
pubmed:issnType
Print
pubmed:volume
131
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5367-80
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:15469974-Adaptor Proteins, Vesicular Transport, pubmed-meshheading:15469974-Animals, pubmed-meshheading:15469974-Calcium-Binding Proteins, pubmed-meshheading:15469974-Cell Communication, pubmed-meshheading:15469974-Cell Differentiation, pubmed-meshheading:15469974-Cell Proliferation, pubmed-meshheading:15469974-Cholesterol, LDL, pubmed-meshheading:15469974-Drosophila Proteins, pubmed-meshheading:15469974-Drosophila melanogaster, pubmed-meshheading:15469974-Endocytosis, pubmed-meshheading:15469974-Gene Expression Regulation, Developmental, pubmed-meshheading:15469974-Hedgehog Proteins, pubmed-meshheading:15469974-Intercellular Signaling Peptides and Proteins, pubmed-meshheading:15469974-Intracellular Signaling Peptides and Proteins, pubmed-meshheading:15469974-Ligands, pubmed-meshheading:15469974-Membrane Proteins, pubmed-meshheading:15469974-Receptors, Notch, pubmed-meshheading:15469974-Signal Transduction, pubmed-meshheading:15469974-Ubiquitin, pubmed-meshheading:15469974-Vesicular Transport Proteins, pubmed-meshheading:15469974-Wing
pubmed:year
2004
pubmed:articleTitle
Drosophila Epsin mediates a select endocytic pathway that DSL ligands must enter to activate Notch.
pubmed:affiliation
Howard Hughes Medical Institute, Department of Genetics and Development, Columbia University College of Physicians and Surgeons, 701 West 168th Street, New York, NY 10032, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't