Linked Life Data

19690049

Source:http://linkedlifedata.com/resource/pubmed/id/19690049

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 18
pubmed:dateCreated
2009-9-3
pubmed:abstractText
Macropinosomes are large endocytic vesicles that form in ruffling regions of plasma membrane. To analyze signal organization relative to ruffle closure into circular ruffles and cup closure into macropinosomes, this study used quantitative microscopy to measure 3' phosphoinositides and small-GTPase activities in a representative subset of forming macropinosomes. Macropinocytosis was stimulated by the addition of macrophage colony-stimulating factor (M-CSF) to macrophages expressing fluorescent reporter proteins. Ratiometric and fluorescence resonance energy transfer (FRET) microscopy determined that Rac1 activity and phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P(3)] levels increased transiently, peaking 26-30 seconds after ruffle closure. Three-dimensional reconstruction of cells labeled with the fluorescent dye FM4-64 showed that PtdIns(3,4,5)P(3) was restricted to open, circular cups in the plasma membrane. Quantitative fluorescence microscopic methods determined the timing of cup closure, which followed 40-100 seconds after Rac1 and PtdIns(3,4,5)P(3) deactivation and coincided with accumulation of phosphatidylinositol 3-phosphate and Rab5a. Thus, ruffle closure creates a circular domain of plasma membrane that localizes the activation and deactivation of Rac1 and phosphoinositide 3-kinase (PI3K), followed by recruitment of Rab5a and the contractile activities of cup closure.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1477-9137
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
122
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3250-61
pubmed:dateRevised
2011-8-1
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Sequential signaling in plasma-membrane domains during macropinosome formation in macrophages.
pubmed:affiliation
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural