| Abstract Detail
Chromatin Ndamukong, Ivan [1], Al Abdallat, Ayed [2], Madhusoodhanan L., Sreedevi [3], Avramova, Zoya [4]. The Arabidopsis TrxG (ATX1) complex; Putative involvement of Myotubularin 1. The accessibility of genes to the transcription machinery is regulated by chromatin structure connected, at the molecular level, to covalent modifications of the histone tails. Reversible, heritable changes in gene expression controlled by chromatin structure are defined as epigenetic. Currently, the polycomb (PcG) and trithorax (trxG) group proteins are known epigenetic regulators. They function as antagonistic multi-protein complexes to maintain the repressed/activated transcriptional states respectively. Among the active components of these complexes are histone methyltransferases providing methylation marks at specific lysine residues of the core histones. PcG and trxG complexes are evolutionarily conserved, characterized in yeast and animal systems. PcG complexes are characterized in plants as well but components of a trithorax-associated complex have not been isolated.
An Arabidopsis homolog of trithorax ATX1 has histone H3K4 methyl-transferase activity involved in gene regulation. To isolate ATX1 partners, we have expressed the ATX1 as a tandem affinity tagged protein, and are in the process of purifying and characterizing proteins that co-purify. Bimolecular fluorescence complementation assay (BiFC) will be used to validate direct protein-protein interactions.
ATX1 participates also in a signal transduction pathway involving phosphatidyl inositol-5 phosphate (PI5P). PI5P binds to ATX1, influencing its distribution in the cell and affecting targeted genes’ expression. Exploring further the ATX1-PI5P pathway, we study the involvement of myotubularin1 (MYO1). It produces the ligand PI5P by dephosphorylating the substrate PI3,5P. Using biochemical and cytological approaches we study the role of MYO1 as a possible link in the phospholipid signaling and epigenetic regulation mechanisms in Arabidopsis.
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1 - University of Nebraska Lincoln, School of Biological Sciences, 302 Manter Hall, 1104 T Street, Lincoln, NE, 68588, USA
2 - University of Jordan,, Faculty of Agriculture, Amman 11942, Jordan
3 - University of Nebraska, School of Biological Sciences
4 - University of Nebraska Lincoln, School of Biological Sciences
Keywords:
epigenetics
trithorax
Signaling
TAP tag.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P39002
Abstract ID:348 |
