Next Meeting: February 27th 2014, IAB, 10:00AM

Our next meeting will be on Thursday, February 27th 2014 10am. Please note that the location changed, it is at the IAB (access).

The speakers will be :
Seminar by François Parcy (iRTSV, Grenoble)
Structure, function and evolution of the LEAFY master floral regulator

Short talk: Joanna Timmins (IBS, Grenoble)
DNA double-strand break repair in Deinococcus radiodurans

Short talk: Jorge Dias (EMBL)
Structural analysis of theNon-Specific Lethal Complex reveals dichotomy of WDR5 interactions with MLL complexes

Coffee break and lunch will be provided by Active Motif, who is sponsoring our meetings.

Abstracts:
Seminar by François Parcy (iRTSV, Grenoble)
Structure, function and evolution of the LEAFY master floral regulator
LEAFY is a key transcription factor controlling both the outgrowth and the floral fate of the group of stem cells that form flowers. It is highly conserved and present in all land plants, mostly as a single copy gene. Using a combination of large scale genomic and biochemical studies, we built and validated a predictive model capturing LEAFY DNA binding specificity in Arabidopsis.
We studied the evolution of this property throughout plants and showed that LEAFY changed DNA binding specificity at least twice during evolution; we provide a structural explanation for these changes as well as a plausible smooth evolutionary pathway to explain how plants could tolerate that an essential factor evolved independently of duplications.
In addition to its DNA binding domain, LEAFY also possesses a second conserved domain. By solving its crystallographic structure, we showed that it is a multimerization domain. We combined a biochemical approach, ChIP-seq experiments and the LFY DNA binding predictive model to show that oligomerization has several functions, some expected and some more surprising. Our study enlightens the mechanisms that govern the access of a transcription factor to various types of genomic regions.
More information:
Chahtane et al. Plant Journal 2013
Moyroud et al. Plant Cell 2011
Sayou et al. Science 2014 and http://youtu.be/Yvk3ond-WHk