Sandbox Reserved 829: Difference between revisions
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===='''Functions with DNA'''==== | ===='''Functions with DNA'''==== | ||
This flexibility of homeodomains in binding DNA may facilitate diverses functions of the PDX-1 transcription factor. Indeed, the PDX-1 protein has multiple functional roles in the developing of the pancreas, in mature pancreatic β and δ-cells, and neural cells. As a transcription factor, | This flexibility of homeodomains in binding DNA may facilitate diverses functions of the PDX-1 transcription factor. Indeed, the PDX-1 protein has multiple functional roles in the developing of the pancreas, in mature pancreatic β and δ-cells, and neural cells. As a transcription factor, PDX-1 is able to regulate a lot of different genes. | ||
It regulates differentiation of the duodenum and stomach and is involved as a key regulator of pancreas development.<ref>doi: 10.1091/mbc.E09-03-0203</ref> Indeed, PDX-1 evolves during the life from a differenciation factor during embryogenesis to a regulation factor of gene transcription of proteins which regulate the rate of glucose of the islets of Langerhans in adults. In the mature pancreas Pdx1 is expressed in β and δ-cells that secrete the endocrine hormones called respectively insulin and somatostatin. <ref>PMID : 15028942 </ref> | It regulates differentiation of the duodenum and stomach and is involved as a key regulator of pancreas development.<ref>doi: 10.1091/mbc.E09-03-0203</ref> Indeed, PDX-1 evolves during the life from a differenciation factor during embryogenesis to a regulation factor of gene transcription of proteins which regulate the rate of glucose of the islets of Langerhans in adults. In the mature pancreas Pdx1 is expressed in β and δ-cells that secrete the endocrine hormones called respectively insulin and somatostatin. <ref>PMID : 15028942 </ref> | ||
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In neural cells, PDX-1 utilizes a different binding site on the somatostatin promoter than in δ-cells, suggesting a distinct protein complex. PDX-1 interacts also with the basic helix-loop-helix (bHLH) factor E47/NeuroD. | In neural cells, PDX-1 utilizes a different binding site on the somatostatin promoter than in δ-cells, suggesting a distinct protein complex. PDX-1 interacts also with the basic helix-loop-helix (bHLH) factor E47/NeuroD. | ||
In pancreatic acinar cells, | In pancreatic acinar cells, PDX-1 interacts with Pbx1b and Mrg1 to regulate the elastase I gene. | ||
Disordered sequences outside of the homeodomain can influence DNA binding specificity. Moreover, phosphorylation or sumoylation are important for nuclear localization and may affect activity. The activity of PDX-1 is regulated by recruiting different coactivators and corepressors to non-conserved regions outside of the homeodomain. | Disordered sequences outside of the homeodomain can influence DNA binding specificity. Moreover, phosphorylation or sumoylation are important for nuclear localization and may affect activity. The activity of PDX-1 is regulated by recruiting different coactivators and corepressors to non-conserved regions outside of the homeodomain. | ||
