2qdi
From Proteopedia
Drosophila OBP LUSH D118A mutation
Structural highlights
Function[OB76A_DROME] Odorant-binding protein required for olfactory behavior and for activity of pheromone-sensitive neurons. Binds to alcohols and mediates avoidance behavior to high concentrations of alcohols, the alcohol-binding possibly resulting in activation of receptors on T2B neurons, the activation of these receptors inhibiting these neurons. Acts in concert with Snmp and lush to capture cVA molecules on the surface of Or67d expressing olfactory dendrites and facilitate their transfer to the odorant-receptor Orco complex. Required for cVA response, probably by binding to VA. May act by serving as an adapter that bridges the presence of gaseous pheromone molecules, cVA, to activation of specific neuronal receptors expressed on T1 olfactory neurons, possibly via a specific conformational change induced by cVA that in turn activates T1 receptors. T1 neurons are excited by the pheromone VA, while T2 neurons are inhibited by alcohols. Also binds to phthalates.[1] [2] [3] [4] [5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDetection of volatile odorants by olfactory neurons is thought to result from direct activation of seven-transmembrane odorant receptors by odor molecules. Here, we show that detection of the Drosophila pheromone, 11-cis vaccenyl acetate (cVA), is instead mediated by pheromone-induced conformational shifts in the extracellular pheromone-binding protein, LUSH. We show that LUSH undergoes a pheromone-specific conformational change that triggers the firing of pheromone-sensitive neurons. Amino acid substitutions in LUSH that are predicted to reduce or enhance the conformational shift alter sensitivity to cVA as predicted in vivo. One substitution, LUSH(D118A), produces a dominant-active LUSH protein that stimulates T1 neurons through the neuronal receptor components Or67d and SNMP in the complete absence of pheromone. Structural analysis of LUSH(D118A) reveals that it closely resembles cVA-bound LUSH. Therefore, the pheromone-binding protein is an inactive, extracellular ligand converted by pheromone molecules into an activator of pheromone-sensitive neurons and reveals a distinct paradigm for detection of odorants. Activation of pheromone-sensitive neurons is mediated by conformational activation of pheromone-binding protein.,Laughlin JD, Ha TS, Jones DN, Smith DP Cell. 2008 Jun 27;133(7):1255-65. PMID:18585358[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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