Poster: Regulation of gene expression

Abs # 755: Expression and Autoregulation of AGL15, a Member of the MADS-box Family

Presenter:	Zhu, Cong , czhu0@uky.edu
Authors	Zhu, Cong  (A)   Perry, Sharyn E. (A)
Affiliations:	(A): University Of Kentucky

AGL15 is an Arabidopsis thaliana MADS-domain regulatory factor that is preferentially expressed during embryogenesis, but is also expressed at lower amounts in subsets of cells after completion of germination. To gain insight into the regulation of expression of AGL15, we have initiated characterization of regulatory regions of AGL15. To find the potential cis regulatory elements, a series of deletions of a previously characterized reporter construct (Fernandez et al., 2000, Plant Cell 12: 183-197) were carried out to dissect the promoter region of AGL15. We identified potential positive and negative cis elements in the 5' regulatory region of AGL15 and defined a region involved in expression in response to auxin. Expression of AGL15 responds to accumulation amounts and forms of AGL15, indicating a role for feedback regulation of this gene. This feedback loop may be due to direct or indirect regulation of AGL15. At least three potential binding sites for MADS-domain proteins are present within the 5กฏ-regulatory region of AGL15. A combination of in vivo and in vitro binding site studies and site-directed mutagenesis were performed to determine whether these cis elements are relevant for autoregulation of AGL15. Results will be presented and discussed.