Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1995-4-27
pubmed:databankReference
pubmed:abstractText
The beta subunit of human chorionic gonadotropin (CG beta) is encoded by a cluster of six genes, which have developed through gene duplication from an ancestral LH beta gene. Despite approximately 90% sequence homology between the CG beta and LH beta promoters, the CG beta gene is expressed in the placenta, whereas the LH beta promoter is active only in the pituitary. The CG beta gene uses a TATA-less promoter that is located upstream of the transcriptional start site used by the homologous LH beta gene. The purpose of this study was to use the high degree of homology among members of the CG beta gene cluster and between the CG beta and LH beta promoters to localize regulatory elements that confer CG beta expression in the placenta. The 5'-flanking regions of the different CG beta genes were cloned and expressed in JEG-3 placental cells. Naturally occurring sequence variations were correlated with promoter activity and used to identify candidate regulatory elements. Exchanges of homologous sequences in the CG beta 5 and LH beta proximal identified three separate regions between -362 and +104 that are necessary for full basal expression of the CG beta promoter. Site-directed mutagenesis of four evolutionarily divergent sequences near the CG beta transcription start site confirmed the importance of multiple distinct regulatory elements as each of these mutations resulted in an 80% decrease in promoter activity.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0303-7207
pubmed:author
pubmed:issnType
Print
pubmed:volume
106
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
111-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:7534731-8-Bromo Cyclic Adenosine Monophosphate, pubmed-meshheading:7534731-Base Sequence, pubmed-meshheading:7534731-Cell Line, pubmed-meshheading:7534731-Chorionic Gonadotropin, pubmed-meshheading:7534731-Chorionic Gonadotropin, beta Subunit, Human, pubmed-meshheading:7534731-DNA, pubmed-meshheading:7534731-Female, pubmed-meshheading:7534731-Gene Expression, pubmed-meshheading:7534731-Humans, pubmed-meshheading:7534731-Luteinizing Hormone, pubmed-meshheading:7534731-Molecular Sequence Data, pubmed-meshheading:7534731-Mutagenesis, Site-Directed, pubmed-meshheading:7534731-Peptide Fragments, pubmed-meshheading:7534731-Placenta, pubmed-meshheading:7534731-Plasmids, pubmed-meshheading:7534731-Promoter Regions, Genetic, pubmed-meshheading:7534731-Recombinant Fusion Proteins, pubmed-meshheading:7534731-Regulatory Sequences, Nucleic Acid, pubmed-meshheading:7534731-Structure-Activity Relationship, pubmed-meshheading:7534731-Transfection
pubmed:year
1994
pubmed:articleTitle
Multiple promoter elements in the human chorionic gonadotropin beta subunit genes distinguish their expression from the luteinizing hormone beta gene.
pubmed:affiliation
Thyroid Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't