A determinant of odorant specificity is located at the extracellular loop 2-transmembrane domain 4 interface of an Anopheles gambiae odorant receptor subunit

David T. Hughes, Guirong Wang, Laurence J. Zwiebel, Charles W Luetje

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

To explore the structural basis for odorant specificity in odorant receptors of the human malaria vector mosquito, Anopheles gambiae, odorant-binding subunits (Agam\Ors) expressed in Xenopus oocytes in combination with Agam\Orco (coreceptor subunit) were assayed by 2-electrode voltage clamp against 25 structurally related odorants. Agam\Or13 and Agam\Or15 display 82% amino acid identity and had similar, but somewhat distinct odorant response profiles. The ratio of acetophenone to 4-methylphenol responses was used in a mutation-based analysis of Agam\Or15, interchanging 37 disparate residues between Agam\Or15 and Agam\Or13. Eleven mutations caused significant changes in odorant responsiveness. Mutation of alanine 195 resulted in the largest shift in response ratio from Agam\Or15 toward Agam\Or13. Concentration-response analysis for a series of mutations of residue 195 revealed a large effect on acetophenone sensitivity, with EC50 values varying by >1800-fold and correlating with residue side chain length. Similar results were obtained for propiophenone and benzaldehyde. But, for other odorants, such as 4-methylphenol, 4-methylbenzaldehyde, and 4-methylpropiophenone, the effect of mutation was much smaller (EC50 values varied by ≤16-fold). These results show that alanine 195, putatively located at the second extracellular loop/fourth transmembrane domain interface, plays a critical role in determining the odorant response specificity of Agam\Or15.

Original languageEnglish (US)
Pages (from-to)761-769
Number of pages9
JournalChemical Senses
Volume39
Issue number9
DOIs
StatePublished - Nov 1 2014

Fingerprint

Odorant Receptors
Anopheles gambiae
Mutation
Alanine
Propiophenones
Xenopus
Odorants
Malaria
Oocytes
Electrodes
Amino Acids

Keywords

  • electrophysiology
  • insect
  • olfaction
  • receptor
  • structure
  • Xenopus oocytes

ASJC Scopus subject areas

  • Medicine(all)

Cite this

A determinant of odorant specificity is located at the extracellular loop 2-transmembrane domain 4 interface of an Anopheles gambiae odorant receptor subunit. / Hughes, David T.; Wang, Guirong; Zwiebel, Laurence J.; Luetje, Charles W.

In: Chemical Senses, Vol. 39, No. 9, 01.11.2014, p. 761-769.

Research output: Contribution to journalArticle

Hughes, David T. ; Wang, Guirong ; Zwiebel, Laurence J. ; Luetje, Charles W. / A determinant of odorant specificity is located at the extracellular loop 2-transmembrane domain 4 interface of an Anopheles gambiae odorant receptor subunit. In: Chemical Senses. 2014 ; Vol. 39, No. 9. pp. 761-769.
@article{96e252fd00894cc7985af8e51f53edfe,
title = "A determinant of odorant specificity is located at the extracellular loop 2-transmembrane domain 4 interface of an Anopheles gambiae odorant receptor subunit",
abstract = "To explore the structural basis for odorant specificity in odorant receptors of the human malaria vector mosquito, Anopheles gambiae, odorant-binding subunits (Agam\Ors) expressed in Xenopus oocytes in combination with Agam\Orco (coreceptor subunit) were assayed by 2-electrode voltage clamp against 25 structurally related odorants. Agam\Or13 and Agam\Or15 display 82{\%} amino acid identity and had similar, but somewhat distinct odorant response profiles. The ratio of acetophenone to 4-methylphenol responses was used in a mutation-based analysis of Agam\Or15, interchanging 37 disparate residues between Agam\Or15 and Agam\Or13. Eleven mutations caused significant changes in odorant responsiveness. Mutation of alanine 195 resulted in the largest shift in response ratio from Agam\Or15 toward Agam\Or13. Concentration-response analysis for a series of mutations of residue 195 revealed a large effect on acetophenone sensitivity, with EC50 values varying by >1800-fold and correlating with residue side chain length. Similar results were obtained for propiophenone and benzaldehyde. But, for other odorants, such as 4-methylphenol, 4-methylbenzaldehyde, and 4-methylpropiophenone, the effect of mutation was much smaller (EC50 values varied by ≤16-fold). These results show that alanine 195, putatively located at the second extracellular loop/fourth transmembrane domain interface, plays a critical role in determining the odorant response specificity of Agam\Or15.",
keywords = "electrophysiology, insect, olfaction, receptor, structure, Xenopus oocytes",
author = "Hughes, {David T.} and Guirong Wang and Zwiebel, {Laurence J.} and Luetje, {Charles W}",
year = "2014",
month = "11",
day = "1",
doi = "10.1093/chemse/bju048",
language = "English (US)",
volume = "39",
pages = "761--769",
journal = "Chemical Senses",
issn = "0379-864X",
publisher = "Oxford University Press",
number = "9",

}

TY - JOUR

T1 - A determinant of odorant specificity is located at the extracellular loop 2-transmembrane domain 4 interface of an Anopheles gambiae odorant receptor subunit

AU - Hughes, David T.

AU - Wang, Guirong

AU - Zwiebel, Laurence J.

AU - Luetje, Charles W

PY - 2014/11/1

Y1 - 2014/11/1

N2 - To explore the structural basis for odorant specificity in odorant receptors of the human malaria vector mosquito, Anopheles gambiae, odorant-binding subunits (Agam\Ors) expressed in Xenopus oocytes in combination with Agam\Orco (coreceptor subunit) were assayed by 2-electrode voltage clamp against 25 structurally related odorants. Agam\Or13 and Agam\Or15 display 82% amino acid identity and had similar, but somewhat distinct odorant response profiles. The ratio of acetophenone to 4-methylphenol responses was used in a mutation-based analysis of Agam\Or15, interchanging 37 disparate residues between Agam\Or15 and Agam\Or13. Eleven mutations caused significant changes in odorant responsiveness. Mutation of alanine 195 resulted in the largest shift in response ratio from Agam\Or15 toward Agam\Or13. Concentration-response analysis for a series of mutations of residue 195 revealed a large effect on acetophenone sensitivity, with EC50 values varying by >1800-fold and correlating with residue side chain length. Similar results were obtained for propiophenone and benzaldehyde. But, for other odorants, such as 4-methylphenol, 4-methylbenzaldehyde, and 4-methylpropiophenone, the effect of mutation was much smaller (EC50 values varied by ≤16-fold). These results show that alanine 195, putatively located at the second extracellular loop/fourth transmembrane domain interface, plays a critical role in determining the odorant response specificity of Agam\Or15.

AB - To explore the structural basis for odorant specificity in odorant receptors of the human malaria vector mosquito, Anopheles gambiae, odorant-binding subunits (Agam\Ors) expressed in Xenopus oocytes in combination with Agam\Orco (coreceptor subunit) were assayed by 2-electrode voltage clamp against 25 structurally related odorants. Agam\Or13 and Agam\Or15 display 82% amino acid identity and had similar, but somewhat distinct odorant response profiles. The ratio of acetophenone to 4-methylphenol responses was used in a mutation-based analysis of Agam\Or15, interchanging 37 disparate residues between Agam\Or15 and Agam\Or13. Eleven mutations caused significant changes in odorant responsiveness. Mutation of alanine 195 resulted in the largest shift in response ratio from Agam\Or15 toward Agam\Or13. Concentration-response analysis for a series of mutations of residue 195 revealed a large effect on acetophenone sensitivity, with EC50 values varying by >1800-fold and correlating with residue side chain length. Similar results were obtained for propiophenone and benzaldehyde. But, for other odorants, such as 4-methylphenol, 4-methylbenzaldehyde, and 4-methylpropiophenone, the effect of mutation was much smaller (EC50 values varied by ≤16-fold). These results show that alanine 195, putatively located at the second extracellular loop/fourth transmembrane domain interface, plays a critical role in determining the odorant response specificity of Agam\Or15.

KW - electrophysiology

KW - insect

KW - olfaction

KW - receptor

KW - structure

KW - Xenopus oocytes

UR - http://www.scopus.com/inward/record.url?scp=84923107538&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84923107538&partnerID=8YFLogxK

U2 - 10.1093/chemse/bju048

DO - 10.1093/chemse/bju048

M3 - Article

C2 - 25270378

AN - SCOPUS:84923107538

VL - 39

SP - 761

EP - 769

JO - Chemical Senses

JF - Chemical Senses

SN - 0379-864X

IS - 9

ER -