Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1993-7-13
pubmed:abstractText
Transcription of the L-type pyruvate kinase (L-PK) gene is induced in response to increased carbohydrate metabolism in the liver. We have demonstrated previously that a segment of the 5'-flanking region of the L-PK gene between -183 and -96 is necessary and sufficient for the glucose response in primary hepatocytes. To explore the protein factors that are involved in carbohydrate regulation, we have performed mutational analyses and in vitro binding studies of this segment. Sequences critical for the glucose response were mapped from -171 to -124. This segment contains the consensus binding sites for two nuclear transcription factors: LF-A1 and MLTF. Both factors are capable of binding to the corresponding L-PK sites in vitro. Mutational and functional analyses indicated that LF-A1 is indeed involved in glucose induction of the L-PK gene. The PK MLTF-like site consists of two imperfect CACGTG motifs, the core binding site for a family of transcription factors related to c-myc. Unexpectedly, mutations in either motif that resulted in defective glucose stimulation retained in vitro binding to MLTF. Furthermore, an authentic MLTF binding site from the adenovirus major late promoter was not functionally interchangeable with the natural sequence. These data indicate that binding of MLTF, in presence of LF-A1, is not capable of supporting the glucose response. Conversion of either imperfect motif to CACGTG within the context of the mutations disrupting the opposite site restored the response to elevated glucose. Thus, the factor that recognizes the PK MLTF-like site and participates in mediating the carbohydrate response of the L-PK gene appears to be a member of the c-myc family distinct from MLTF.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:geneSymbol
c-myc
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12787-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8509413-Animals, pubmed-meshheading:8509413-Base Sequence, pubmed-meshheading:8509413-Cell Nucleus, pubmed-meshheading:8509413-Cells, Cultured, pubmed-meshheading:8509413-Cloning, Molecular, pubmed-meshheading:8509413-DNA Mutational Analysis, pubmed-meshheading:8509413-DNA-Binding Proteins, pubmed-meshheading:8509413-Escherichia coli, pubmed-meshheading:8509413-Gene Expression Regulation, Enzymologic, pubmed-meshheading:8509413-Glucose, pubmed-meshheading:8509413-Liver, pubmed-meshheading:8509413-Male, pubmed-meshheading:8509413-Molecular Sequence Data, pubmed-meshheading:8509413-Mutagenesis, Insertional, pubmed-meshheading:8509413-Mutagenesis, Site-Directed, pubmed-meshheading:8509413-Oligodeoxyribonucleotides, pubmed-meshheading:8509413-Point Mutation, pubmed-meshheading:8509413-Proto-Oncogene Proteins c-myc, pubmed-meshheading:8509413-Pyruvate Kinase, pubmed-meshheading:8509413-Rats, pubmed-meshheading:8509413-Rats, Sprague-Dawley, pubmed-meshheading:8509413-Transcription Factors, pubmed-meshheading:8509413-Transfection, pubmed-meshheading:8509413-Viral Proteins
pubmed:year
1993
pubmed:articleTitle
Carbohydrate regulation of the rat L-type pyruvate kinase gene requires two nuclear factors: LF-A1 and a member of the c-myc family.
pubmed:affiliation
Department of Biochemistry, University of Minnesota, Minneapolis 55455.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.