Linked Life Data

12553421

Source:http://linkedlifedata.com/resource/pubmed/id/12553421

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2003-1-29
pubmed:abstractText
The retinol/retinol-binding protein/transthyretin complex, that carries and delivers hydrophobic retinol molecules to target cells, is assembled in the hepatocyte endoplasmic reticulum. In this paper, we review data related to events that lead to the formation of this complex, including transthyretin oligomerization and retinol-binding protein secretion. Our studies on transthyretin oligomerization have demonstrated that cleavage of signal peptide and the environment of endoplasmic reticulum influence transthyretin oligomerization. In vitro, mutated transthyretin without signal sequence fails to form dimers, while wild-type transthyretin is translocated into the microsomes where it forms dimers and small amounts of tetramers. In vivo, tetramers were detected in HepG2 cells but not in transfected Cos cells, suggesting that tissue-specific factors affect tetramer stability. In vitamin A deficiency, retinol-binding protein secretion is blocked and the protein accumulates in the endoplasmic reticulum, from where it is promptly released after retinol repletion. We use MMH cells to identify factors involved in complex formation, retention and secretion, the crucial steps to understand the molecular mechanisms underlying vitamin A homeostasis. In parallel, studies on vitamin A transport in fish are in progress; retinol-binding protein and transthyretin have already been characterized in different fish species.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1434-6621
pubmed:author
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1211-20
pubmed:dateRevised
2005-11-16
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Hepatic synthesis, maturation and complex formation between retinol-binding protein and transthyretin.
pubmed:affiliation
Istituto Nazionale di Ricerca per gli Alimenti e la Nutrizione, Roma, Italy. gaetani@inran.it
pubmed:publicationType
Journal Article, Review