Interactions Between Odorants and Glutathione Transferases in the Human Olfactory Cleft

2020 ◽  
Vol 45 (8) ◽  
pp. 645-654
Author(s):  
Mathieu Schwartz ◽  
Franck Menetrier ◽  
Jean-Marie Heydel ◽  
Evelyne Chavanne ◽  
Philippe Faure ◽  
...  
Keyword(s):  
Olfactory Receptors ◽  
Glutathione Transferases ◽  
Odor Perception ◽  
Metabolizing Enzymes ◽  
Odorant Binding Proteins ◽  
X Ray Crystallography ◽  
Odorant Binding ◽  
Gst Family ◽  
Human Olfaction

Abstract Xenobiotic metabolizing enzymes and other proteins, including odorant-binding proteins located in the nasal epithelium and mucus, participate in a series of processes modulating the concentration of odorants in the environment of olfactory receptors (ORs) and finely impact odor perception. These enzymes and transporters are thought to participate in odorant degradation or transport. Odorant biotransformation results in 1) changes in the odorant quantity up to their clearance and the termination of signaling and 2) the formation of new odorant stimuli (metabolites). Enzymes, such as cytochrome P450 and glutathione transferases (GSTs), have been proposed to participate in odorant clearance in insects and mammals as odorant metabolizing enzymes. This study aims to explore the function of GSTs in human olfaction. Using immunohistochemical methods, GSTs were found to be localized in human tissues surrounding the olfactory epithelium. Then, the activity of 2 members of the GST family toward odorants was measured using heterologously expressed enzymes. The interactions/reactions with odorants were further characterized using a combination of enzymatic techniques. Furthermore, the structure of the complex between human GSTA1 and the glutathione conjugate of an odorant was determined by X-ray crystallography. Our results strongly suggest the role of human GSTs in the modulation of odorant availability to ORs in the peripheral olfactory process.

scholarly journals The role of SNMPs in insect olfaction

2020 ◽  
Author(s):  
Sina Cassau ◽  
Jürgen Krieger
Keyword(s):  
Membrane Proteins ◽  
Olfactory System ◽  
Critical Role ◽  
Olfactory Receptors ◽  
Wide Distribution ◽  
Insect Olfaction ◽  
Survival And Reproduction ◽  
Odorant Binding ◽  
Encoding Genes

AbstractThe sense of smell enables insects to recognize olfactory signals crucial for survival and reproduction. In insects, odorant detection highly depends on the interplay of distinct proteins expressed by specialized olfactory sensory neurons (OSNs) and associated support cells which are housed together in chemosensory units, named sensilla, mainly located on the antenna. Besides odorant-binding proteins (OBPs) and olfactory receptors, so-called sensory neuron membrane proteins (SNMPs) are indicated to play a critical role in the detection of certain odorants. SNMPs are insect-specific membrane proteins initially identified in pheromone-sensitive OSNs of Lepidoptera and are indispensable for a proper detection of pheromones. In the last decades, genome and transcriptome analyses have revealed a wide distribution of SNMP-encoding genes in holometabolous and hemimetabolous insects, with a given species expressing multiple subtypes in distinct cells of the olfactory system. Besides SNMPs having a neuronal expression in subpopulations of OSNs, certain SNMP types were found expressed in OSN-associated support cells suggesting different decisive roles of SNMPs in the peripheral olfactory system. In this review, we will report the state of knowledge of neuronal and non-neuronal members of the SNMP family and discuss their possible functions in insect olfaction.

scholarly journals Odorant-Binding Proteins and Xenobiotic Metabolizing Enzymes: Implications in Olfactory Perireceptor Events

2013 ◽  
Vol 296 (9) ◽  
pp. 1333-1345 ◽  
Author(s):  
Jean-Marie Heydel ◽  
Alexandra Coelho ◽  
Nicolas Thiebaud ◽  
Arièle Legendre ◽  
Anne-Marie Le Bon ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Metabolizing Enzymes ◽  
Odorant Binding Proteins ◽  
Xenobiotic Metabolizing Enzymes ◽  
Perireceptor Events ◽  
Odorant Binding

Wild-Type and Mutant Bovine Odorant-Binding Proteins To Probe the Role of the Quaternary Structure Organization in the Protein Thermal Stability

2008 ◽  
Vol 7 (12) ◽  
pp. 5221-5229 ◽  
Author(s):  
Anna Marabotti ◽  
Andrea Scirè ◽  
Maria Staiano ◽  
Roberta Crescenzo ◽  
Vincenzo Aurilia ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Binding Proteins ◽  
Quaternary Structure ◽  
Wild Type ◽  
Odorant Binding Proteins ◽  
Protein Thermal Stability ◽  
Odorant Binding

scholarly journals Antennal Enriched Odorant Binding Proteins Are Required for Odor Communication in Glossina f. fuscipes

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 541
Author(s):  
Souleymane Diallo ◽  
Mohd Shahbaaz ◽  
JohnMark O. Makwatta ◽  
Jackson M. Muema ◽  
Daniel Masiga ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Tissue Expression ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Odorant Binding Proteins ◽  
Male Antenna ◽  
Female Antenna ◽  
Odor Communication ◽  
Odorant Binding

Olfaction is orchestrated at different stages and involves various proteins at each step. For example, odorant-binding proteins (OBPs) are soluble proteins found in sensillum lymph that might encounter odorants before reaching the odorant receptors. In tsetse flies, the function of OBPs in olfaction is less understood. Here, we investigated the role of OBPs in Glossina fuscipes fuscipes olfaction, the main vector of sleeping sickness, using multidisciplinary approaches. Our tissue expression study demonstrated that GffLush was conserved in legs and antenna in both sexes, whereas GffObp44 and GffObp69 were expressed in the legs but absent in the antenna. GffObp99 was absent in the female antenna but expressed in the male antenna. Short odorant exposure induced a fast alteration in the transcription of OBP genes. Furthermore, we successfully silenced a specific OBP expressed in the antenna via dsRNAi feeding to decipher its function. We found that silencing OBPs that interact with 1-octen-3-ol significantly abolished flies’ attraction to 1-octen-3-ol, a known attractant for tsetse fly. However, OBPs that demonstrated a weak interaction with 1-octen-3-ol did not affect the behavioral response, even though it was successfully silenced. Thus, OBPs’ selective interaction with ligands, their expression in the antenna and their significant impact on behavior when silenced demonstrated their direct involvement in olfaction.

scholarly journals Ir76b is a Co-receptor for Amine Responses in Drosophila Olfactory Neurons

2021 ◽  
Vol 15 ◽  
Author(s):  
Alina Vulpe ◽  
Karen Menuz
Keyword(s):  
Olfactory Receptor ◽  
Olfactory Receptors ◽  
Olfactory Receptor Neurons ◽  
Odorant Receptors ◽  
Olfactory Neurons ◽  
Bona Fide ◽  
Receptor Neurons ◽  
Large Families ◽  
Odorant Binding

Two large families of olfactory receptors, the Odorant Receptors (ORs) and Ionotropic Receptors (IRs), mediate responses to most odors in the insect olfactory system. Individual odorant binding “tuning” OrX receptors are expressed by olfactory neurons in basiconic and trichoid sensilla and require the co-receptor Orco. The situation for IRs is more complex. Different tuning IrX receptors are expressed by olfactory neurons in coeloconic sensilla and rely on either the Ir25a or Ir8a co-receptors; some evidence suggests that Ir76b may also act as a co-receptor, but its function has not been systematically examined. Surprisingly, recent data indicate that nearly all coeloconic olfactory neurons co-express Ir25a, Ir8a, and Ir76b. Here, we demonstrate that Ir76b and Ir25a function together in all amine-sensing olfactory receptor neurons. In most neurons, loss of either co-receptor abolishes amine responses. In contrast, amine responses persist in the absence of Ir76b or Ir25a in ac1 sensilla but are lost in a double mutant. We show that responses mediated by acid-sensing neurons do not require Ir76b, despite their expression of this co-receptor. Our study also demonstrates that one population of coeloconic olfactory neurons exhibits Ir76b/Ir25a-dependent and Orco-dependent responses to distinct odorants. Together, our data establish the role of Ir76b as a bona fide co-receptor, which acts in partnership with Ir25a. Given that these co-receptors are among the most highly conserved olfactory receptors and are often co-expressed in chemosensory neurons, our data suggest Ir76b and Ir25a also work in tandem in other insects.

STEROID HORMONE METABOLISM IN RESPONSIVE TISSUES IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S279-S294 ◽  
Author(s):  
Paul Robel
Keyword(s):  
Steroid Hormone ◽  
Physiological Activity ◽  
Physiological State ◽  
Target Cells ◽  
Target Tissue ◽  
Hormone Metabolism ◽  
Metabolizing Enzymes ◽  
Relationship Of

ABSTRACT Of the information available on steroid hormone metabolism in responsive tissues, only that relating hormone metabolism to physiological activity is reviewed, i. e. metabolite activity in isolated in vitro systems, binding of metabolites to target tissue receptors, specific steroid hormone metabolizing enzymes and relationship of hormone metabolism to target organ physiological state. Further, evidence is presented in the androgen field, demonstrating 5α-reduced metabolites, formed inside the target cells, as active compounds. This has led to a consideration of testosterone as a »prehormone«. The possibility that similar events take place in tissues responding to progesterone is discussed. Finally, the role of hormone metabolism in the regulation of hormone availability and/or renewal in target cells is discussed. In this context, reference is made to the potential role of plasma binding proteins and cytosol receptors.

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