| dc.contributor.author | Lyons, Peter J. | en_US |
| dc.date.accessioned | 2014-10-21T12:36:05Z | |
| dc.date.available | 2005 | |
| dc.date.issued | 2005 | en_US |
| dc.identifier.other | AAINR08414 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/54745 | |
| dc.description | Adipocyte Enhancer-binding Protein 1 (AEBP1) is a transcriptional repressor of the aP2 gene, which encodes the adipocyte lipid binding protein and is involved in the differentiation of preadipocytes into mature adipocytes. Other functions have also been ascribed to AEBP1 which play a part in its regulation of adipogenesis. These include the regulation of phosphorylation of the extracellular-regulated kinases 1 and 2 (ERK1/2) MAP kinases, the regulation of the stability of PTEN, a protein and lipid phosphatase, and the interaction with the gamma5 subunit of a heterotrimeric G protein leading to an attenuation of the transcriptional repression activity of AEBP1. AEBP1 contains a conserved carboxypeptidase domain that is critical for its function as a transcriptional repressor. | en_US |
| dc.description | Homology modeling and multiple alignment of AEBP1 homologues were performed to identify putative domains and critical residues that were then deleted or mutated in mouse AEBP1. Expression and purification of wild-type and mutant recombinant AEBP1 proteins were optimized. S668 in mouse AEBP1 was identified by site-directed mutagenesis as the residue critical for phosphorylation of AEBP1 by MAP kinase, both in vitro and in vivo. T623, however, is the only potential MAP kinase phosphorylation site conserved in human AEBP1, and mutagenesis of T623 followed by kinase and transcriptional assays suggested that this threonine might be phosphorylated and that phosphorylation status might affect DNA binding and transcriptional repression by AEBP1. While AEBP1 was able to bind DNA, electrophoretic mobility shift and luciferase reporter assays suggested that AEBP1 might function predominantly as a co-repressor, independent of DNA binding. A possible corepression mechanism was suggested by the identification of AEBP1 as a Ca2+/calmodulin-interacting component of a histone H3 arginine kinase complex. Molecular modeling and pulldown experiments suggested the carboxypeptidase domain of AEBP1 might interact with the C-terminus of histone H3. A model for AEBP1 transcriptional repression through interaction with and subsequent phosphorylation of histone H3 in an arginine kinase complex, regulated by interaction of the C-terminus of AEBP1 with calmodulin, is presented. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 2005. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Molecular. | en_US |
| dc.title | Transcriptional repression by adipocyte enhancer binding protein 1. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
