Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-5-31
pubmed:abstractText
Integrin Associated Protein (IAP, CD47) is a ubiquitous integral membrane protein implicated in processes (in mice) that range from inhibiting clearance by phagocytes [Oldenborg et al., Science 2000; Gardai et al., Cell 2005] to neutrophil motility [Lindberg et al., Science 1996]. SIRPalpha is CD47's main receptor on phagocytes plus a number of other cell types, and SIRPalpha-CD47 interactions in clusters are believed to mediate signaling. However, considerable species differences in CD47 sequence as well as differences in CD47 extractability from mouse cells versus man motivate a characterization of mobility, clusterability, and kinetics under force of CD47-SIRPalpha. Despite similar levels of CD47 on red cells from mouse and man, we find an effective avidity of SIRPalpha-CD47 for mouse appears higher than for human. Both mouse and human CD47 show clustering by multivalent SIRPalpha complexes, but only mouse cells aggregate with CD47 concentrating at cell-cell contacts. This proves consistent with fluorescence imaged micro-deformation, which indicates near-complete mobility of CD47 on mouse cells compared to only about 30-40% mobility on normal human cells. To qualify the method, we also show that disrupting cellular F-actin dramatically increases the mobility of integral membrane proteins. Furthermore, atomic force microscopy probing of cell membranes with human SIRPalpha confirms the species-specific interactions and provides evidence of clustering and adhesion on short time scales, but it also shows surprisingly strong forces in detachment for a signaling complex. The results thus highlight major species differences in CD47-SIRPalpha interactions and CD47 integration, suggesting that signaling by CD47 in man may be qualitatively different from mouse.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1079-9796
pubmed:author
pubmed:issnType
Print
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
364-72
pubmed:dateRevised
2007-2-6
pubmed:meshHeading
pubmed:articleTitle
Membrane mobility and clustering of Integrin Associated Protein (IAP, CD47)--major differences between mouse and man and implications for signaling.
pubmed:affiliation
Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural