Linked Life Data

17635917

Source:http://linkedlifedata.com/resource/pubmed/id/17635917

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
2007-9-10
pubmed:abstractText
Microsomal triglyceride transfer protein (MTP) has been studied extensively, primarily because of its role in the assembly of very low density lipoproteins by the liver and chylomicrons by the intestine. Recent studies have suggested that MTP may also play key roles in other cellular processes. In this paper we report the identification of a novel splice variant of MTP in mice. This isoform, MTP-B, has a unique first exon located approximately 2.7 kilobases upstream of canonical MTP (MTP-A) exon 1. The alternative exon encodes 35 amino acids compared with 20 amino acids encoded by exon 1 of MTP-A. MTP-B represents approximately 90% of total MTP mRNA in mouse adipocytes and 3T3-L1 cells and <5% in mouse liver and intestine. Expression of the alternate isoform in mouse liver was confirmed by mass spectrometry. Co-transfection of COS cells with truncated forms of apoB and either MTP-A or MTP-B demonstrated that both isoforms are effective in the assembly and secretion of nascent apoB-containing lipoproteins. Confocal microscopy of 3T3-L1 cells transfected with enhanced green fluorescent protein or DsRed fusions of the two proteins revealed that MTP-A is localized to the endoplasmic reticulum, whereas MTP-B localizes primarily to the Golgi complex in these cells. We conclude that MTP-B functions similarly to MTP-A in lipoprotein assembly. However, in nonlipoprotein-secreting cells, such as the adipocyte, MTP-B may have different localization properties, perhaps reflecting a distinct role in lipid storage and mobilization.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
26981-8
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Identification of a novel isoform of microsomal triglyceride transfer protein.
pubmed:affiliation
Department of Internal Medicine, University of Iowa School of Medicine, Iowa City, IA 52242, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural