Abscisic acid (ABA) is a plant hormone. ABA functions in many plant developmental processes, including seed and bud dormancy, the control of organ size and stomatal closure. It is especially important for plants in the response to environmental stresses, including drought, soil salinity, cold tolerance, freezing tolerance, heat stress and heavy metal ion tolerance. ABA-mediated signaling also plays an important part in plant responses to environmental stress and plant pathogens. Abscisic acid is also produced in the roots in response to decreased soil water potential (which is associated with dry soil) and other situations in which the plant may be under stress. ABA then translocates to the leaves, where it rapidly alters the osmotic potential of stomatal guard cells, causing them to shrink and stomata to close. Since the discovery of its structure, advances have been made in understanding ABA metabolism, synthesis, and hormone-responsive genes; however, the understanding of the early stage of ABA perception by the plant cell remained a mystery. During the past decade receptor proteins for the other traditional plant hormones (auxin, gibberellins, cytokinin, and ethylene) were discovered, while the identity of the ABA receptor remained elusive, creating controversy. Finally, in 2009, two research groups converged upon the PYR/PYL/RCAR family of soluble proteins in Arabidopsis (Arabidopsis thaliana), which evidence indicates are one type of ABA-binding receptor-like proteins. This protein family has 14 members, almost all of which appear capable of forming an ABA-receptor complex that is able to activate the transcription of ABA-responsive genes. Here you can see the crystal structure of the tomato SLPYL1 ABA receptor in its dimeric form (PDB code: 7Z1Q)
#molecularart ... #immolecular ... #plant ... #hormone ... #abcisic ... #acid ... #receptor ... #dimer
Receptor structure rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #plant ... #hormone ... #abcisic ... #acid ... #receptor ... #dimer
Receptor structure rendered with @proteinimaging and depicted with @corelphotopaint
