English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

The peptide hormone glucagon is expressed in A cells of the pancreatic islets due to an interaction between multiple regulatory elements within the 5'-flanking region of its gene directing glucagon gene transcription. An A-cell-specific enhancer-like element in the rat glucagon gene, G3, contains two domains, both of which are necessary for G3 activity. Domain A of the G3 element comprises a sequence motif, PISCES, that is also found in control elements of the rat insulin I and somatostatin genes exhibiting cell-specific transcriptional activities distinct from G3. In this study, the nuclear proteins binding to domain B of G3 were characterized. In electrophoretic mobility shift assays using nuclear extracts from a glucagon-producing islet cell line, it was observed that the binding specificity of G3-domain-B-binding proteins is related to that of winged helix proteins supporting the hypothesis that the proteins binding to domain B of G3 may belong to the winged helix protein family of transcription factors. The overexpression of a dominant-negative winged helix protein mutant (derived from HNF-3) virtually abolished the transcriptional activity of G3 in a glucagon-expressing islet cell line. These results suggest that the unique A-cell-specific basal transcriptional activity of the glucagon G3 element depends on a combination of at least two proteins, the islet specific PISCES-binding protein and a more widely expressed winged helix protein.

Glucagon Gene G3 Enhancer: Evidence that Activity Depends on Combination of an Islet-Specific Factor and a Winged Helix Protein