Growth and Vegetative Development
Mudgil, Yashwanti , Jones, Alan .
N-myc Down Regulated Arabidopsis homologue (AtNDR1) operates in Gbeta-gamma signaling pathway to regulate meristem development.
In animals, the basic units of the heterotrimeric G-protein signaling network include a cell-surface receptor (GPCR), a coupling complex comprised of alpha, beta, and gamma subunits (G protein), and a downstream target (effector). Sequential activation of these G protein components result in changes in cellular activities such as ion flux, protein trafficking, and gene expression. Plants also utilize signaling through G proteins but there are few candidates for the upstream GPCRs and the downstream effectors. In the current study, we are seeking downstream effectors of G protein signaling. Toward this, we performed a yeast three-hybrid screen using Arabidopsis Gbeta1 and Ggamma1/or Ggamma 2 subunits as baits to screen for physical interactors in an Arabidopsis cDNA expression library. We found and confirmed interaction between the Gbeta-gamma dimer and a protein of unknown function designated NDR (N-Myc Down Regulated) in animals. The sunflower NDR homolog, designated SF21, is expressed the highest in pollen and in the transmitting tissues of pistils, and it shows multiple alternative and organ-specific splicing transcripts. Arabidopsis has three NDR proteins (AtNDR1◊3) which are highly similar, between them NDR2 and 3 are predominately expressed in pollen. All three members interact with Gbeta-gamma in the yeast 3-hybrid configuration. Over expression studies indicate its role in vegetative branching and flower development. Preliminary down regulation studies by micro RNA indicates it has important role in primary vegetative growth. Biochemical characterization and down regulation in other available G protein component mutant background are in progress to further dissect out its function in Gbeta-gamma signaling.
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1 - University of North Carolina,, Department of Biology, CB# 3280 University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
2 - University of North Carolina, Department of Biology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM