Linked Life Data

16222699

Source:http://linkedlifedata.com/resource/pubmed/id/16222699

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-12-26
pubmed:abstractText
Lipid rafts, membrane sub-domains enriched in sterols and sphingolipids, are controversial because demonstrations of rafts have often utilized fixed cells. We showed in living sperm that the ganglioside G(M1) localized to a micron-scale membrane sub-domain in the plasma membrane overlying the acrosome. We investigated four models proposed for membrane sub-domain maintenance. G(M1) segregation was maintained in live sperm incubated under non-capacitating conditions, and after sterol efflux, a membrane alteration necessary for capacitation. The complete lack of G(M1) diffusion to the post-acrosomal plasma membrane (PAPM) in live cells argued against the transient confinement zone model. However, within seconds after cessation of sperm motility, G(M1) dramatically redistributed several microns from the acrosomal sub-domain to the post-acrosomal, non-raft sub-domain. This redistribution was not accompanied by movement of sterols, and was induced by the pentameric cholera toxin subunit B (CTB). These data argued against a lipid-lipid interaction model for sub-domain maintenance. Although impossible to rule out a lipid shell model definitively, mice lacking caveolin-1 maintained segregation of both sterols and G(M1), arguing against a role for lipid shells surrounding caveolin-1 in sub-domain maintenance. Scanning electron microscopy of sperm freeze-dried without fixation identified cytoskeletal structures at the sub-domain boundary. Although drugs used to disrupt actin and intermediate filaments had no effect on the segregation of G(M1), we found that disulfide-bonded proteins played a significant role in sub-domain segregation. Together, these data provide an example of membrane sub-domains extreme in terms of size and stability of lipid segregation, and implicate a protein-based membrane compartmentation mechanism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9541
pubmed:author
pubmed:copyrightInfo
Copyright 2005 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:volume
206
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
636-46
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Segregation of micron-scale membrane sub-domains in live murine sperm.
pubmed:affiliation
The James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural