Linked Life Data

12093533

Source:http://linkedlifedata.com/resource/pubmed/id/12093533

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2002-7-2
pubmed:abstractText
Although the most exogenous lipids enter the cell via the LDL-receptor pathway, the mechanism(s) whereby lipids leave the lysosome for transport to intracellular sites are not clearly resolved. As shown herein, expression of sterol carrier protein-2 (SCP-2) in transfected L-cells altered lysosomal membrane lipid distribution, dynamics, and response to lipid transfer proteins. SCP-2 expression decreased the mass of cholesterol and lyso-bis-phosphatidic acid [LBPA], as well as the ratios of cholesterol/phospholipid and polyunsaturated/monounsaturated fatty acids esterified to lysosomal membrane phospholipids. Concomitantly, a fluorescent sterol transfer assay showed that SCP-2 expression decreased the initial rates of spontaneous and SCP-2-mediated sterol transfer 5.5- and 3.8-fold, respectively, from lysosomal membranes isolated from SCP-2 expressing cells as compared to controls. SCP-2, sphingomyelinase, low density lipoprotein, and high density lipoprotein directly enhanced the initial rates of sterol transfer from isolated lysosomal membranes by 50-, 12-, 4-, and 5-fold, respectively. In contrast, albumin and cholesterol esterase had no effect on lysosomal sterol transfer. Spontaneous sterol was very slow, t(1/2)>4 days, regardless of the source of the lysosomal membrane, while SCP-2 added in vitro induced formation of rapid and slowly transferable sterol pools in lysosomal membranes of control cells. In contrast, SCP-2 did not induce formation of a rapidly transferable sterol domain in lysosomal membranes isolated from SCP-2 expressing cells. These data suggest that SCP-2 expression selectively shifted the distribution of lipids (cholesterol, LBPA, esterified polyunsaturated fatty acids) away from lysosomal membranes. Furthermore, the cholesterol depleted lysosomal membrane isolated from SCP-2 expressing cells was resistant to additional direct action of SCP-2 to further enhance sterol transfer and induce rapidly transferable sterol pools in the lysosomal membrane.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0009-3084
pubmed:author
pubmed:issnType
Print
pubmed:volume
116
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19-38
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Molecular and fluorescent sterol approaches to probing lysosomal membrane lipid dynamics.
pubmed:affiliation
Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.