Linked Life Data

12660248

Source:http://linkedlifedata.com/resource/pubmed/id/12660248

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
2003-5-26
pubmed:abstractText
In mammals, methionine adenosyltransferase (MAT), the enzyme responsible for S-adenosylmethionine (AdoMet) synthesis, is encoded by two genes, MAT1A and MAT2A. In liver, MAT1A expression is associated with high AdoMet levels and a differentiated phenotype, whereas MAT2A expression is associated with lower AdoMet levels and a dedifferentiated phenotype. In the current study, we examined regulation of MAT2A gene expression by l-methionine availability using HepG2 cells. In l-methionine-deficient cells, MAT2A gene expression is rapidly induced, and methionine adenosyltransferase activity is increased. Restoration of l-methionine rapidly down-regulates MAT2A mRNA levels; for this effect, l-methionine needs to be converted into AdoMet. This novel action of AdoMet is not mediated through a methyl transfer reaction. MAT2A gene expression was also regulated by 5'-methylthioadenosine, but this was dependent on 5'-methylthioadenosine conversion to methionine through the salvage pathway. The transcription rate of the MAT2A gene remained unchanged during l-methionine starvation; however, its mRNA half-life was significantly increased (from 100 min to more than 3 h). The effect of l-methionine withdrawal on MAT2A mRNA stabilization requires both gene transcription and protein synthesis. We conclude that MAT2A gene expression is modulated as an adaptive response of the cell to l-methionine availability through its conversion to AdoMet.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19885-90
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
L-methionine availability regulates expression of the methionine adenosyltransferase 2A gene in human hepatocarcinoma cells: role of S-adenosylmethionine.
pubmed:affiliation
Laboratorio de Proteómica, Genómica y Bioinformática, and División de Hepatología y Terapia Génica, Universidad de Navarra, Facultad de Medicina, 31008 Pamplona, Spain.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't