Linked Life Data

8939918

Source:http://linkedlifedata.com/resource/pubmed/id/8939918

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
47
pubmed:dateCreated
1997-1-13
pubmed:databankReference
pubmed:abstractText
Cat-1 is a protein with a dual function, a high affinity, low capacity cationic amino acid transporter of the y+ system and the receptor for the ecotropic retrovirus. We have suggested that Cat-1 is required in the regenerating liver for the transport of cationic amino acids and polyamines in the late G1 phase, a process that is essential for liver cells to enter mitosis. In our earlier studies we had shown that the cat-1 gene is silent in the quiescent liver but is induced in response to hormones, insulin, and glucocorticoids, and partial hepatectomy. Here we demonstrate that cat-1 is a classic delayed early growth response gene in the regenerating liver, since induction of its expression is sensitive to cycloheximide, indicating that protein synthesis is required. The peak of accumulation of the cat-1 mRNA (9-fold) by 3 h was not associated with increased transcriptional activity of the cat-1 gene in the regenerating liver, indicating post-transcriptional regulation of expression of this gene. Induction of the cat-1 gene results in the accumulation of two mRNA species (7.9 and 3.4 kilobase pairs (kb)). Both mRNAs hybridize with the previously described rat cat-1/2.9-kb cDNA clone. However, the 3' end of a longer rat cat-1 cDNA (rat cat-1/6.5-kb) hybridizes only to the 7.9-kb mRNA transcript. Sequence analysis of this clone indicated that the two mRNA species result from the use of alternative polyadenylation signals. The 6. 5-kb clone contains a number of AT-rich mRNA destabilizing sequences which is reflected in the half-life of the cat-1 mRNAs (90 min for 7. 9-kb mRNA and 250 min for 3.4-kb mRNA). Treatment of rats with cycloheximide superinduces the level of the 7.9-kb cat-1 mRNA in the kidney, spleen, and brain, but not in the liver, suggesting that cell type-specific labile factors are involved in its regulation. We conclude that the need for protein synthesis for induction of the cat-1 mRNA, the short lived nature of the mRNAs, and the multiple sites for regulation of gene expression indicate a tight control of expression of the cat-1 gene within the regenerating liver and suggest that y+ cationic amino acid transport in liver cells is regulated at the molecular level.
pubmed:grant
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
22
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29799-806
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8939918-Amino Acid Transport Systems, Basic, pubmed-meshheading:8939918-Animals, pubmed-meshheading:8939918-Base Sequence, pubmed-meshheading:8939918-Brain, pubmed-meshheading:8939918-Carrier Proteins, pubmed-meshheading:8939918-Cations, pubmed-meshheading:8939918-Cycloheximide, pubmed-meshheading:8939918-DNA, Complementary, pubmed-meshheading:8939918-Gene Expression Regulation, pubmed-meshheading:8939918-Half-Life, pubmed-meshheading:8939918-Kidney, pubmed-meshheading:8939918-Liver Regeneration, pubmed-meshheading:8939918-Male, pubmed-meshheading:8939918-Membrane Proteins, pubmed-meshheading:8939918-Molecular Sequence Data, pubmed-meshheading:8939918-RNA, Messenger, pubmed-meshheading:8939918-Rats, pubmed-meshheading:8939918-Rats, Sprague-Dawley, pubmed-meshheading:8939918-Receptors, Virus, pubmed-meshheading:8939918-Retroviridae, pubmed-meshheading:8939918-Spleen, pubmed-meshheading:8939918-Transcription, Genetic, pubmed-meshheading:8939918-Tumor Cells, Cultured
pubmed:year
1996
pubmed:articleTitle
Molecular sites of regulation of expression of the rat cationic amino acid transporter gene.
pubmed:affiliation
Department of Nutrition, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't