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Titolo:
HUMAN CHORIONIC SOMATOMAMMOTROPIN GENE ENHANCER ACTIVITY IS DEPENDENTAN THE BLOCKADE OF A REPRESSOR MECHANISM
Autore:
LYTRAS A; CATTINI PA;
Indirizzi:
UNIV MANITOBA,DEPT PHYSIOL,770 BANNATYNE AVE WINNIPEG R3E 0W3 MB CANADA
Titolo Testata:
Molecular endocrinology
fascicolo: 4, volume: 8, anno: 1994,
pagine: 478 - 489
SICI:
0888-8809(1994)8:4<478:HCSGEA>2.0.ZU;2-3
Fonte:
ISI
Lingua:
ENG
Soggetto:
HUMAN PLACENTAL-LACTOGEN; RAT PROLACTIN PROMOTER; GROWTH-HORMONE GENE; TRANSCRIPTIONAL ENHANCER; SV40 ENHANCER; BINDING; EXPRESSION; PROTEIN; SEQUENCE; ACTIVATOR;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
27
Recensione:
Indirizzi per estratti:
Citazione:
A. Lytras e P.A. Cattini, "HUMAN CHORIONIC SOMATOMAMMOTROPIN GENE ENHANCER ACTIVITY IS DEPENDENTAN THE BLOCKADE OF A REPRESSOR MECHANISM", Molecular endocrinology, 8(4), 1994, pp. 478-489

Abstract

The human chorionic somatomammotropin genes (hCS-A and -B) are expressed at high levels in the syncytiotrophoblast during pregnancy. A 22-base-pair (bp) transcriptional enhancer factor-1 (TEF-1) element in a 1022-bp fragment of the hCS-B 3'-flanking DNA (nucleotides 1-1022) was shown to be important for efficient promoter activity in placental cells. However, the TEF-1 site used alone does not contain all of the information required for the complete enhancer activity seen with the 1022-bp fragment. A 241-bp region of the 1022-bp fragment (nucleotides 1-241) maintains full enhancer activity in placental cells. Interactionsbetween placental nuclear factors and sequences distinct from the TEF-1 element (nucleotides 117-139) were identified by gel mobility shiftassay using the up-stream region corresponding to nucleotides 1-80. Interaction between these factors and the TEF-1 element was indicated by competition of the 1-80 bp region for complex formation by a TEF-1 site. We mutated sequences within the 1-80 bp region of the 241-bp enhancer fragment and assessed the enhancer function of wild-type and modified 241-bp fragments. We identified a sequence (DF-1 site) upstream of the TEF-1 site which is required for hCS-B enhancer function. DF-1 derepresses a repressor mechanism present in the 241-bp fragment that inhibits TEF-1 activity. A component of this repressor mechanism (RF-1 site) is present in the 1-80 bp region adjacent to the DF-1 site. Gel mobility shift competition analysis shows that the RF-1 and DF-1 sitesparticipate in the formation of a common complex or compete for common protein factors in a tissue-specific manner.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/09/20 alle ore 10:49:06