Presentation Details
| Evolutionarily Conserved Mechanisms of Short-Chain Aldehyde Recognition by the Olfactory Receptor OR6B1 Haruto Kudo, Reina Kanemaki, Masafumi Yohda, Yosuke Fukutani. Tokyo University of Agriculture and Technology, Koganei, Japan |
Abstract
Animals discriminate odorants through combinatorial activation patterns of olfactory receptors (ORs). Short-chain aldehydes, including acetaldehyde, have characteristic pungent odors and occur widely in environmental and biological contexts. Using a vapor-phase stimulation assay, we previously identified OR6B1 as the only human OR robustly responsive to acetaldehyde and propanal. OR6B1 is broadly conserved among mammals (Niimura et al., Genome Research, 2014), and BLAST searches further suggest the presence of orthologs in reptiles and birds, raising the possibility that aldehyde recognition is conserved across vertebrates. Here, we expressed 19 OR6B1 orthologs in a HEK293T-based heterologous expression system and compared their cell-surface localization and aldehyde responsiveness. Functional expression varied markedly among species. The canine OR6B1 ortholog exhibited the highest membrane localization, consistent with enhanced structural stability, and several reptile orthologs also showed robust surface expression. 15 orthologs responded to a panel of linear aldehydes with carbon chain lengths of C2–C7, similar to human OR6B1, and residues surrounding the predicted agonist-binding pocket were highly conserved. In contrast, a tortoise OR6B1 ortholog carrying a single substitution near the pocket did not respond to acetaldehydes, but instead responded to longer-chain aldehydes, indicating a shift in ligand selectivity. OR6B1 orthologs from dolphin and platypus did not show functional agonist responses under our conditions. Together, these results support an evolutionarily maintained role of OR6B1 in short-chain aldehyde detection, particularly in terrestrial vertebrates, while highlighting lineage-specific diversification of expression properties and ligand selectivity.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.
Content Locked. Log into a registered attendee account to access this presentation.