Linked Life Data

10938271

Source:http://linkedlifedata.com/resource/pubmed/id/10938271

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
44
pubmed:dateCreated
2000-11-20
pubmed:abstractText
We report the subcellular localization of enzymes involved in phosphatidylserine biosynthesis in mammalian cells. Several lines of evidence suggest that phosphatidylserine synthase-1 (PSS1) is highly enriched in mitochondria-associated membranes (MAM) and is largely excluded from the bulk of the endoplasmic reticulum (ER). Taking advantage of the substrate specificity of PSS1, we showed that (i) MAM contain choline exchange activity, whereas this activity is very low in the bulk of the ER, (ii) serine exchange activity is inhibited by choline to a much greater extent in MAM than in ER, and (iii) MAM use phosphatidylcholine and phosphatidylethanolamine as substrates for phosphatidylserine biosynthesis, whereas the ER utilizes only phosphatidylethanolamine. According to immunoblotting of proteins from both CHO-K1 cells and murine liver, PSS1 is localized to MAM, and in hepatoma cells stably expressing PSS1 this protein is highly enriched in MAM. Since the ER contains serine and ethanolamine exchange activities, we had predicted that PSS2 would account for the serine exchange activity in the ER. Unexpectedly, using immunoblotting experiments, we found that (i) PSS2 of CHO-K1 cells is present only in MAM and (ii) PSS2 is restricted to MAM of McArdle cells expressing recombinant PSS2. These data leave open the question of which enzyme imparts PSS activity to the ER and suggest that a third isoform of PSS might be located in the ER.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
34534-40
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Phosphatidylserine synthase-1 and -2 are localized to mitochondria-associated membranes.
pubmed:affiliation
Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2S2, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't