Structure and regulation of the salivary gland secretion protein gene Sgs-1 of Drosophila melanogaster.
Genetics
; 153(2): 753-62, 1999 Oct.
Article
em En
| MEDLINE
| ID: mdl-10511555
ABSTRACT
The Drosophila melanogaster gene Sgs-1 belongs to the secretion protein genes, which are coordinately expressed in salivary glands of third instar larvae. Earlier analysis had implied that Sgs-1 is located at the 25B2-3 puff. We cloned Sgs-1 from a YAC covering 25B2-3. Despite using a variety of vectors and Escherichia coli strains, subcloning from the YAC led to deletions within the Sgs-1 coding region. Analysis of clonable and unclonable sequences revealed that Sgs-1 mainly consists of 48-bp tandem repeats encoding a threonine-rich protein. The Sgs-1 inserts from single lambda clones are heterogeneous in length, indicating that repeats are eliminated. By analyzing the expression of Sgs-1/lacZ fusions in transgenic flies, cis-regulatory elements of Sgs-1 were mapped to lie within 1 kb upstream of the transcriptional start site. Band shift assays revealed binding sites for the transcription factor fork head (FKH) and the factor secretion enhancer binding protein 3 (SEBP3) at positions that are functionally relevant. FKH and SEBP3 have been shown previously to be involved in the regulation of Sgs-3 and Sgs-4. Comparison of the levels of steady state RNA and of the transcription rates for Sgs-1 and Sgs-1/lacZ reporter genes indicates that Sgs-1 RNA is 100-fold more stable than Sgs-1/lacZ RNA. This has implications for the model of how Sgs transcripts accumulate in late third instar larvae.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas do Grude Salivar de Drosophila
/
Regulação da Expressão Gênica
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Drosophila melanogaster
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
1999
Tipo de documento:
Article