Linked Life Data

2606938

Source:http://linkedlifedata.com/resource/pubmed/id/2606938

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1990-2-22
pubmed:abstractText
We used the acrosome reaction of boar sperm cells to study the dynamics of surface transmembrane glycoproteins (TMG) during a secretory process. The acrosome reaction is the Ca2+-dependent fusion of a large cytoplasmic vesicle (the acrosome) with the overlying segment of the plasma membrane (acrosomal cap) that leads to the release of the acrosomal enzymes. After triggering the acrosome reaction in vitro (2 mM-CaCl2 in the presence of 10 microM-A23187), we used freeze-fracture electron microscopy to follow the topographical rearrangement of a population of acrosomal-cap large intramembrane particles that correspond to transmembrane proteins that bind wheat germ agglutinin. We found that these TMG move in the direction of either one of two opposite poles, proximal and distal, of the acrosomal cap. This bimodal movement of the TMG reorganizes the acrosomal cap into three extensive domains. The first two, on the apical rim and on the equator, are membrane domains to which the TMG are directed and where they accumulate. The third, a large in-between area of protein clearing, corresponds to the region from which TMG were preferentially located before displacement induced by the Ca2+ effect. The topography of these new membrane domains of the acrosomal cap becomes coincident with that of the structural domains of the subjacent acrosomal membrane. Mirroring of the acrosomal membrane by the plasma membrane is followed by fusion between the two membranes, formation of an exquisite labyrinth of hybrid-membrane tubules, followed by fission and release of the acrosomal contents through intertubular fenestrae.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:volume
93 ( Pt 3)
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
467-79
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Bimodal redistribution of surface transmembrane glycoproteins during Ca2+-dependent secretion (acrosome reaction) in boar spermatozoa.
pubmed:affiliation
Membrane Biology Section, National Cancer Institute, Frederick Cancer Research Facility, Frederick, Maryland 21701.
pubmed:publicationType
Journal Article