Odorant-binding protein explained

Odorant-binding proteins (OBPs) are small (10 to 30 kDa) soluble proteins secreted by auxiliary cells surrounding olfactory receptor neurons, including the nasal mucus of many vertebrate species and in the sensillar lymph of chemosensory sensilla of insects. OBPs are characterized by a specific protein domain that comprises six α-helices joined by three disulfide bonds. Although the function of the OBPs as a whole is not well established, it is believed that they act as odorant transporters, delivering the odorant molecules to olfactory receptors in the cell membrane of sensory neurons.

The olfactory receptors of terrestrial animals exist in an aqueous environment, yet detect odorants that are primarily hydrophobic.[1] The aqueous solubility of hydrophobic odorants is greatly enhanced via odorant-binding proteins, which exist in the extracellular fluid surrounding the odorant receptors. This family is composed of pheromone binding proteins (PBP), which are male-specific and associate with pheromone-sensitive neurons and general-odorant-binding proteins (GOBP).

These proteins were initially identified on the basis of their ability to bind with moderate-affinity radioactively labeled odorants.[2] [3]

Structure

OBPs are small proteins on the order of 14 kDa in size. All odorant binding proteins are believed to have a common structure despite their genetic diversity and highly variable primary structures.[4] In vertebrates, OBPs are a part of the lipocalin family. They are structurally characterized by a β-barrel motif composed of antiparallel β-sheets. Insect OBPs share very little amino acid sequence similarity to vertebrate OBPs as they mainly contain α-helical domains.[5] [6] [7] OBPs are divergent across and within species. The percentage of conserved residues between species has been shown to be as low as 8%. OBPs' have a characteristic signature that is recognized by a conserved pattern of six cysteines that are connected in the protein by three disulfide bridges.[8] Their structures have been investigated to explore new bio-inspired repellents against mosquitoes, with potentially improved OBP binding affinity, selectivity, and reduced volatility.[9] [10]

Function

The functions of odorant binding proteins as a whole is not well understood. They are generally believed to increase the solubility of hydrophobic odorants by binding them and transporting them across the aqueous sensillum lymph to receptors in the dendrites,[11] [5] [12] [13] [14] [15] and several studies support a role for OBPs in olfactory perception in vivo.[16] [17] [18] Some odorant binding proteins are hypothesized to hasten odor response termination by extracting odorant molecules from the sensillar lymph or from receptors themselves.[19] [20] Presently, just one OBP, Obp76a, has been thoroughly investigated in the olfactory system of Drosophila and has a known physiological role.[21] Obp76a, better known as LUSH, is located trichoid sensilla and is necessary for normal response of the odor receptor Or67d to its pheromone ligand cis-vaccenyl acetate (cVA), although responses of Or67d to cVA have been detected in the absence of Obp76a[22] [23] [24] LUSH has also been found to bind cVA in vitro[25] and is known to bind other insect pheromones,[26] short-chain alcohols,[27] [28] and phthalates.[29]

In 2016, Larter et al. found that the deletion of the sole abundant OBP, Obp28a, in ab8 sensilla of Drosophila does not reduce the magnitude of their olfactory responses, suggesting that Obp28a is not required for odorant transport and that ab8 sensilla do not require an abundant OBP. Their results further suggest Obp28a may be buffering changes in the odor environment, possibly as molecular gain control, which has not been previously reported for OBPs.[30]

OBPs are thought to have multiple roles besides olfaction, including reproduction, egg laying and antiinflammatory responses.[31]

Expression

OBPs are numerous and diverse. In Drosophila, they are encoded by 52 genes of the same family yet only share 20% amino acid similarity between themselves. Some are encoded by the most abundant mRNAs of the antennae.[32] [33] Within and between species, OBPs are expressed in several different tissues, including the antennal sensilla,[34] [35] [36] the taste system, and chemosensory organs.[37] [38] [35] [39] [40] They are also known to be ectopically expressed in tissues such as the gut.

Genomic analysis of Drosophila and other insect species (Anopheles gambiae, Apis mellifera, Bombyx mori, and Triboliumcastaneum) has revealed that the OBP genes significantly differ between species. The OBP family contains 21 (in A. mellifera) to 66 genes (in A. gambiae), whereas it ranges from 52 members in Drosophila to 20 in T. castaneum.[41] [42] [43] Generally these genes are irregularly scattered across the genome. Most (69% of the OBP genes in Drosophila) are arranged in small clusters from 2 to 6 OBP genes. The Drosophila OBP gene family has been classified into several subfamilies based on structural features, functional information, and phylogenetic relationships: the Classic, Minus-C, Plus-C, Dimer, PBP/GOBP, ABPI and ABPII, CRLBP, and D7 subfamilies. These subfamilies are unequally distributed across arthropods, even among the dipterans and are totally absent in some species.

See also

Notes and References

  1. Vogt. R. G.. Prestwich. G. D.. Lerner. M. R.. January 1991. Odorant-binding-protein subfamilies associate with distinct classes of olfactory receptor neurons in insects. Journal of Neurobiology. 22. 1. 74–84. 10.1002/neu.480220108. 0022-3034. 2010751.
  2. Pelosi. P.. Baldaccini. N. E.. Pisanelli. A. M.. 1982-01-01. Identification of a specific olfactory receptor for 2-isobutyl-3-methoxypyrazine. The Biochemical Journal. 201. 1. 245–248. 0264-6021. 1163633. 7082286. 10.1042/bj2010245.
  3. Shi. W.. Ostrov. D.A.. 1999-08-25. Gerchman. S.E.. Graziano. V.. Kycia. H.. Studier. B.. Almo. S.C.. Burley. S.K.. PNP Oxidase from Saccharomyces Cerevisiae. 10.2210/pdb1ci0/pdb.
  4. Graham. Laurie A. Davies. Peter L. June 2002. The odorant-binding proteins of Drosophila melanogaster : annotation and characterization of a divergent gene family. Gene. 292. 1–2. 43–55. 10.1016/s0378-1119(02)00672-8. 12119098. 0378-1119. free.
  5. Sandler. Benjamin H. Nikonova. Larisa. Leal. Walter S. Clardy. Jon. February 2000. Sexual attraction in the silkworm moth: structure of the pheromone-binding-protein–bombykol complex. Chemistry & Biology. 7. 2. 143–151. 10.1016/s1074-5521(00)00078-8. 1074-5521. 10662696. free.
  6. Lartigue. Audrey. Campanacci. Valérie. Roussel. Alain. Larsson. Anna M.. Jones. T. Alwyn. Tegoni. Mariella. Cambillau. Christian. 2002-08-30. X-ray Structure and Ligand Binding Study of a Moth Chemosensory Protein. Journal of Biological Chemistry. en. 277. 35. 32094–32098. 10.1074/jbc.M204371200. 0021-9258. 12068017. free.
  7. Tegoni. Mariella. Campanacci. Valérie. Cambillau. Christian. May 2004. Structural aspects of sexual attraction and chemical communication in insects. Trends in Biochemical Sciences. 29. 5. 257–264. 10.1016/j.tibs.2004.03.003. 15130562. 0968-0004.
  8. Pelosi. P.. 2005-01-01. Diversity of Odorant-binding Proteins and Chemosensory Proteins in Insects. Chemical Senses. en. 30. Supplement 1. i291–i292. 10.1093/chemse/bjh229. 15738163. 0379-864X. free.
  9. da Costa. Kauȇ Santana. Galúcio. João Marcos. da Costa. Clauber Henrique Souza. Santana. Amanda Ruslana. dos Santos Carvalho. Vitor. do Nascimento. Lidiane Diniz. Lima e Lima. Anderson Henrique. Neves Cruz. Jorddy. Alves. Claudio Nahum. Lameira. Jerônimo. 2019-12-31. Exploring the Potentiality of Natural Products from Essential Oils as Inhibitors of Odorant-Binding Proteins: A Structure- and Ligand-Based Virtual Screening Approach To Find Novel Mosquito Repellents. ACS Omega. en. 4. 27. 22475–22486. 10.1021/acsomega.9b03157. 2470-1343. 6941369. 31909330.
  10. Thireou. Trias. Kythreoti. Georgia. Tsitsanou. Katerina E.. Koussis. Konstantinos. Drakou. Christina E.. Kinnersley. Julie. Kröber. Thomas. Guerin. Patrick M.. Zhou. Jing-Jiang. Iatrou. Kostas. Eliopoulos. Elias. July 2018. Identification of novel bioinspired synthetic mosquito repellents by combined ligand-based screening and OBP-structure-based molecular docking. Insect Biochemistry and Molecular Biology. en. 98. 48–61. 10.1016/j.ibmb.2018.05.001. 29751047. 21670580 .
  11. Gomez-Diaz. Carolina. Reina. Jaime H.. Cambillau. Christian. Benton. Richard. 2013-04-30. Ligands for Pheromone-Sensing Neurons Are Not Conformationally Activated Odorant Binding Proteins. PLOS Biology. en. 11. 4. e1001546. 10.1371/journal.pbio.1001546. 1545-7885. 3640100. 23637570 . free .
  12. Vogt. R. G.. Riddiford. L. M.. Prestwich. G. D.. 1985-12-01. Kinetic properties of a sex pheromone-degrading enzyme: the sensillar esterase of Antheraea polyphemus. Proceedings of the National Academy of Sciences. en. 82. 24. 8827–8831. 10.1073/pnas.82.24.8827. 0027-8424. 3001718. 391531. 1985PNAS...82.8827V. free.
  13. Wojtasek. Hubert. Leal. Walter S.. 1999-10-22. Conformational Change in the Pheromone-binding Protein fromBombyx mori Induced by pH and by Interaction with Membranes. Journal of Biological Chemistry. en. 274. 43. 30950–30956. 10.1074/jbc.274.43.30950. 0021-9258. 10521490. free.
  14. Xu. PingXi. Atkinson. Rachel. Jones. David N.M.. Smith. Dean P.. January 2005. Drosophila OBP LUSH Is Required for Activity of Pheromone-Sensitive Neurons. Neuron. 45. 2. 193–200. 10.1016/j.neuron.2004.12.031. 15664171. 0896-6273. free.
  15. Vieira. Filipe G.. Rozas. Julio. 2011-01-01. Comparative Genomics of the Odorant-Binding and Chemosensory Protein Gene Families across the Arthropoda: Origin and Evolutionary History of the Chemosensory System. Genome Biology and Evolution. en. 3. 476–490. 10.1093/gbe/evr033. 3134979. 21527792.
  16. Biessmann. Harald. Andronopoulou. Evi. Biessmann. Max R.. Douris. Vassilis. Dimitratos. Spiros D.. Eliopoulos. Elias. Guerin. Patrick M.. Iatrou. Kostas. Justice. Robin W.. 2010-03-01. The Anopheles gambiae Odorant Binding Protein 1 (AgamOBP1) Mediates Indole Recognition in the Antennae of Female Mosquitoes. PLOS ONE. en. 5. 3. e9471. 10.1371/journal.pone.0009471. 1932-6203. 2830424. 20208991. 2010PLoSO...5.9471B. free.
  17. Pelletier. Julien. Guidolin. Aline. Syed. Zainulabeuddin. Cornel. Anthony J.. Leal. Walter S.. 2010-02-27. Knockdown of a Mosquito Odorant-binding Protein Involved in the Sensitive Detection of Oviposition Attractants. Journal of Chemical Ecology. en. 36. 3. 245–248. 10.1007/s10886-010-9762-x. 0098-0331. 2837830. 20191395.
  18. Swarup. S.. Williams. T. I.. Anholt. R. R. H.. 2011-06-14. Functional dissection of Odorant binding protein genes in Drosophila melanogaster. Genes, Brain and Behavior. en. 10. 6. 648–657. 10.1111/j.1601-183x.2011.00704.x. 1601-1848. 3150612. 21605338.
  19. Vogt. Richard G.. Riddiford. Lynn M.. September 1981. Pheromone binding and inactivation by moth antennae. Nature. En. 293. 5828. 161–163. 10.1038/293161a0. 18074618. 1981Natur.293..161V. 4361816. 0028-0836.
  20. Ziegelberger. Gunde. September 1995. Redox-Shift of the Pheromone-Binding Protein in the Silkmoth Antheraea Polyphemus. European Journal of Biochemistry. 232. 3. 706–711. 10.1111/j.1432-1033.1995.tb20864.x. 7588707. 0014-2956.
  21. Laughlin. John D.. Ha. Tal Soo. Jones. David N.M.. Smith. Dean P.. June 2008. Activation of Pheromone-Sensitive Neurons Is Mediated by Conformational Activation of Pheromone-Binding Protein. Cell. 133. 7. 1255–1265. 10.1016/j.cell.2008.04.046. 0092-8674. 4397981. 18585358.
  22. Benton. Richard. Vannice. Kirsten S.. Vosshall. Leslie B.. 2007-10-17. An essential role for a CD36-related receptor in pheromone detection in Drosophila. Nature. En. 450. 7167. 289–293. 10.1038/nature06328. 17943085. 2007Natur.450..289B. 4402715. 0028-0836.
  23. Li. Zhengzheng. Ni. Jinfei D.. Huang. Jia. Montell. Craig. 2014-09-25. Requirement for Drosophila SNMP1 for Rapid Activation and Termination of Pheromone-Induced Activity. PLOS Genetics. en. 10. 9. e1004600. 10.1371/journal.pgen.1004600. 1553-7404. 4177743. 25255106 . free .
  24. van der Goes van Naters. Wynand. Carlson. John R.. April 2007. Receptors and Neurons for Fly Odors in Drosophila. Current Biology. 17. 7. 606–612. 10.1016/j.cub.2007.02.043. 0960-9822. 1876700. 17363256.
  25. Kruse. Schoen W. Zhao. Rui. Smith. Dean P. Jones. David N M. 2003-07-27. Structure of a specific alcohol-binding site defined by the odorant binding protein LUSH from Drosophila melanogaster. Nature Structural & Molecular Biology. En. 10. 9. 694–700. 10.1038/nsb960. 1545-9993. 4397894. 12881720.
  26. Katti. S.. Lokhande. N.. González. D.. Cassill. A.. Renthal. R.. 2012-11-01. Quantitative analysis of pheromone-binding protein specificity. Insect Molecular Biology. en. 22. 1. 31–40. 10.1111/j.1365-2583.2012.01167.x. 0962-1075. 3552018. 23121132.
  27. Bucci. Brigid K.. Kruse. Schoen W.. Thode. Anna B.. Alvarado. Sylvia M.. Jones. David N. M.. February 2006. Effect ofn-Alcohols on the Structure and Stability of theDrosophilaOdorant Binding Protein LUSH†. Biochemistry. en. 45. 6. 1693–1701. 10.1021/bi0516576. 16460016. 0006-2960.
  28. Thode. Anna B.. Kruse. Schoen W.. Nix. Jay C.. Jones. David N.M.. March 2008. The Role of Multiple Hydrogen-Bonding Groups in Specific Alcohol Binding Sites in Proteins: Insights from Structural Studies of LUSH. Journal of Molecular Biology. 376. 5. 1360–1376. 10.1016/j.jmb.2007.12.063. 0022-2836. 2293277. 18234222.
  29. Zhou. Jing-Jiang. Zhang. Guo-An. Huang. Wensheng. Birkett. Michael A. Field. Linda M. Pickett. John A. Pelosi. Paolo. 2004-01-07. Revisiting the odorant-binding protein LUSH ofDrosophila melanogaster: evidence for odour recognition and discrimination. FEBS Letters. en. 558. 1–3. 23–26. 10.1016/s0014-5793(03)01521-7. 14759510. 0014-5793. free.
  30. Larter. Nikki K. Sun. Jennifer S. Carlson. John R. 2016-11-15. Organization and function of Drosophila odorant binding proteins. eLife. en. 5. 10.7554/elife.20242. 2050-084X. 5127637. 27845621 . free .
  31. Pelosi. Paolo. Iovinella. Immacolata. Zhu. Jiao. Wang. Guirong. Dani. Francesca R.. 2018. Beyond chemoreception: diverse tasks of soluble olfactory proteins in insects. Biological Reviews. en. 93. 1. 184–200. 10.1111/brv.12339. 28480618. 1469-185X. free. 2158/1089933. free.
  32. Hekmat-Scafe. Daria S.. Scafe. Charles R.. McKinney. Aimee J.. Tanouye. Mark A.. 2002-09-01. Genome-Wide Analysis of the Odorant-Binding Protein Gene Family in Drosophila melanogaster. Genome Research. en. 12. 9. 1357–1369. 10.1101/gr.239402. 1088-9051. 186648. 12213773.
  33. Menuz. Karen. Larter. Nikki K.. Park. Joori. Carlson. John R.. 2014-11-20. An RNA-Seq Screen of the Drosophila Antenna Identifies a Transporter Necessary for Ammonia Detection. PLOS Genetics. en. 10. 11. e1004810. 10.1371/journal.pgen.1004810. 1553-7404. 4238959. 25412082 . free .
  34. McKenna. M. P.. Hekmat-Scafe. D. S.. Gaines. P.. Carlson. J. R.. 1994-06-10. Putative Drosophila pheromone-binding proteins expressed in a subregion of the olfactory system. The Journal of Biological Chemistry. 269. 23. 16340–16347. 10.1016/S0021-9258(17)34013-9. 0021-9258. 8206941. free.
  35. Pikielny. C.W.. Hasan. G.. Rouyer. F.. Rosbash. M.. January 1994. Members of a family of drosophila putative odorant-binding proteins are expressed in different subsets of olfactory hairs. Neuron. 12. 1. 35–49. 10.1016/0896-6273(94)90150-3. 7545907. 15776205. 0896-6273.
  36. Schultze. Anna. Pregitzer. Pablo. Walter. Marika F.. Woods. Daniel F.. Marinotti. Osvaldo. Breer. Heinz. Krieger. Jürgen. 2013-07-05. The Co-Expression Pattern of Odorant Binding Proteins and Olfactory Receptors Identify Distinct Trichoid Sensilla on the Antenna of the Malaria Mosquito Anopheles gambiae. PLOS ONE. en. 8. 7. e69412. 10.1371/journal.pone.0069412. 1932-6203. 3702612. 23861970. 2013PLoSO...869412S. free.
  37. Galindo. K.. Smith. D. P.. November 2001. A large family of divergent Drosophila odorant-binding proteins expressed in gustatory and olfactory sensilla. Genetics. 159. 3. 1059–1072. 10.1093/genetics/159.3.1059. 0016-6731. 1461854. 11729153.
  38. Jeong. Yong Taek. Shim. Jaewon. Oh. So Ra. Yoon. Hong In. Kim. Chul Hoon. Moon. Seok Jun. Montell. Craig. August 2013. An Odorant-Binding Protein Required for Suppression of Sweet Taste by Bitter Chemicals. Neuron. 79. 4. 725–737. 10.1016/j.neuron.2013.06.025. 0896-6273. 3753695. 23972598.
  39. S.. Shanbhag. S.-K.. Park. C.. Pikielny. R.. Steinbrecht. 2001-05-28. Gustatory organs of Drosophila melanogaster : fine structure and expression of the putative odorant-binding protein PBPRP2. Cell and Tissue Research. en. 304. 3. 423–437. 10.1007/s004410100388. 11456419. 23354983. 0302-766X.
  40. Park. S.-K.. Shanbhag. S. R.. Wang. Q.. Hasan. G.. Steinbrecht. R. A.. Pikielny. C. W.. 2000-03-30. Expression patterns of two putative odorant-binding proteins in the olfactory organs of Drosophila melanogaster have different implications for their functions. Cell and Tissue Research. 300. 1. 181–192. 10.1007/s004410050059. 2024-04-27 . 10805087. 0302-766X.
  41. Forêt. Sylvain. Maleszka. Ryszard. November 2006. Function and evolution of a gene family encoding odorant binding-like proteins in a social insect, the honey bee (Apis mellifera). Genome Research. 16. 11. 1404–1413. 10.1101/gr.5075706. 1088-9051. 1626642. 17065610.
  42. Forêt. Sylvain. Wanner. Kevin W.. Maleszka. Ryszard. January 2007. Chemosensory proteins in the honey bee: Insights from the annotated genome, comparative analyses and expressional profiling. Insect Biochemistry and Molecular Biology. 37. 1. 19–28. 10.1016/j.ibmb.2006.09.009. 0965-1748. 17175443.
  43. Vieira. Filipe G.. Sánchez-Gracia. Alejandro. Rozas. Julio. 2007. Comparative genomic analysis of the odorant-binding protein family in 12 Drosophila genomes: purifying selection and birth-and-death evolution. Genome Biology. 8. 11. R235. 10.1186/gb-2007-8-11-r235. 1474-760X. 2258175. 18039354 . free .