Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 6 février 2014
Amphi 2 (Bâtiment 2 Bis) à 14h
Regulation of the plant steroid receptor activation
UMR0879 RDP Reproduction et Développement des Plantes, Lyon
In plants, receptor kinases form the largest family of membrane receptors (≈420 in Arabidopsis) and they are involved in virtually all aspects of the plant life, including development, immunity and reproduction. Only a few representative receptor kinases have been studied extensively and yet there are many with unknown function (≈400). Additionally, we still know very little on how the activity of these receptors is regulated. The plant growth hormone Brassinosteroid is perceived at the plasma membrane by BRI1, a Leucine-Rich-Repeat receptor kinase (LRR-RK). Here we addressed the molecular mechanisms of BRI1 activation. We report that the BRI1 KINASE INHIBITOR 1 (BKI1) is tyrosine phosphorylated in response to brassinosteroid perception. Phosphorylation occurs within a reiterated [KR][KR] membrane targeting motif, releasing BKI1 into the cytosol and enabling formation of an active signaling complex between BRI1 and its co-receptor BAK1. I will discuss our current model of BKI1 targeting to the plasma membrane and its implication for brassinosteroid signaling.
Contact : Alexandre Martinière