Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2009-5-21
pubmed:abstractText
Serine palmitoyltransferase (SPT) catalyzes the first committed step in sphingolipid biosynthesis. In yeast, SPT is composed of a heterodimer of 2 highly-related subunits, Lcb1p and Lcb2p, and a third subunit, Tsc3p, which increases enzyme activity markedly and is required for growth at elevated temperatures. Higher eukaryotic orthologs of Lcb1p and Lcb2p have been identified, but SPT activity is not highly correlated with coexpression of these subunits and no ortholog of Tsc3p has been identified. Here, we report the discovery of 2 proteins, ssSPTa and ssSPTb, which despite sharing no homology with Tsc3p, each substantially enhance the activity of mammalian SPT expressed in either yeast or mammalian cells and therefore define an evolutionarily conserved family of low molecular weight proteins that confer full enzyme activity. The 2 ssSPT isoforms share a conserved hydrophobic central domain predicted to reside in the membrane, and each interacts with both hLCB1 and hLCB2 as assessed by positive split ubiquitin 2-hybrid analysis. The presence of these small subunits, along with 2 hLCB2 isofoms, suggests that there are 4 distinct human SPT isozymes. When each SPT isozyme was expressed in either yeast or CHO LyB cells lacking endogenous SPT activity, characterization of their in vitro enzymatic activities, and long-chain base (LCB) profiling revealed differences in acyl-CoA preference that offer a potential explanation for the observed diversity of LCB seen in mammalian cells.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-10713067, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-10722759, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-10862608, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-11242106, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-11781309, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-11903061, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-11937514, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-12782147, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-1317856, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-15485854, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-15777716, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-16210380, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-16216550, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-17023427, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-17090526, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-17194770, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-17322298, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-17331073, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-17559874, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-17635905, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-18208516, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-18499644, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-2066332, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-7937952, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-8058731, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-8063782, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-8334704, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-8673084, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-9813126, http://linkedlifedata.com/resource/pubmed/commentcorrection/19416851-9837968
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1091-6490
pubmed:author
pubmed:issnType
Electronic
pubmed:day
19
pubmed:volume
106
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8186-91
pubmed:dateRevised
2010-9-24
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Identification of small subunits of mammalian serine palmitoyltransferase that confer distinct acyl-CoA substrate specificities.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural