Anti-OLFR73 polyclonal Antibody

A multi-gene family of similar to 1000 G protein-coupled olfactory receptors (ORs) constitutes the molecular basis of mammalian olfaction. Due to the lack of structural data its remarkable capacity to detect and discriminate thousands of odorants remains poorly understood on the structural level of the receptor. Using site-directed mutagenesis we transferred ligand specificity between two functionally related ORs and thereby revealed amino acid residues of central importance for odorant recognition and discrimination of the two receptors. By exchanging two of three residues, differing at equivalent positions of the putative odorant binding site between the mouse OR paralogs Olfr73 (mOR-EG) and Olfr74 (mOR-EV), we selectively changed ligand preference but remarkably also signaling activation strength in both ORs. Computer modeling proposed structural details at atomic resolution how the very same odorant molecule might interact with different contact residues to induce different functional responses in two related receptors. Our findings provide a mechanistic explanation of how the olfactory system distinguishes different molecular aspects of a given odorant molecule, and unravel important molecular details of the combinatorial encoding of odorant identity at the OR level.

Gramine is an alkaloid found in giant reed and maple. Many reports discuss the health-beneficial effects of gramine in inflammation, angiogenesis, and cell growth. However, the physiological role of gramine in the odorant-induced signal transduction pathway has not yet been investigated. Therefore, in this study, we aimed to evaluate the effects of gramine on odorant-stimulated non-neuronal 3T3-L1 cells endogenously expressing the murine eugenol receptor, olfr73. We showed that gramine inhibited the eugenol-induced calcium influx and cyclic AMP (cAMP) elevation in the 3T3-L1 cells without any toxicity. In addition, gramine decreased the phosphorylation of protein kinase A and cAMP response element binding protein (CREB), which are known as downstream targets of cAMR in eugenol-stimulated 3T3-L1 cells. These results indicate that gramine suppresses the eugenol-induced signal transduction pathway in non-neuronal 3T3-L1 cells by modulating calcium influx, cAMP levels, and CREB phosphorylation.