GEPHE SUMMARY
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Gephebase Gene
Entry Status
Published
GepheID
GP00000184
Main curator
Courtier
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Other Carnivora
Trait State in Taxon B
Mellivora capensis
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Latin Name
Common Name
carnivores
Synonyms
carnivores
Rank
order
Lineage
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uterostomia; Chordata; Craniata; Vertebrata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Latin Name
Common Name
ratel
Synonyms
ratel; honey badger
Rank
species
Lineage
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Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria; Carnivora; Caniformia; Mustelidae; Mellivoriane; Mellivora
Parent
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Generic Gene Name
CHRNA1
Synonyms
ACHRA; ACHRD; CHRNA; CMS1A; CMS1B; CMS2A; FCCMS; SCCMS; CHNRA
String
Sequence Similarities
Belongs to the ligand-gated ion channel (TC 1.A.9) family. Acetylcholine receptor (TC 1.A.9.1) subfamily. Alpha-1/CHRNA1 sub-subfamily.
GO - Molecular Function
GO:0042166 : acetylcholine binding
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GO - Biological Process
GO:0007165 : signal transduction
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GO - Cellular Component
GO:0005886 : plasma membrane
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UniProtKB
Homo sapiens
Homo sapiens
Mutation #1
Presumptive Null
Molecular Type
Aberration Type
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
Trp187Arg + Phe189Leu
Experimental Evidence
| Taxon A | Taxon B | Position | |
|---|---|---|---|
| Codon | - | - | - |
| Amino-acid | Trp | Arg | 187 |
Authors
Drabeck DH; Dean AM; Jansa SA
Abstract
Honey badgers (Mellivora capensis) prey upon and survive bites from venomous snakes (Family: Elapidae), but the molecular basis of their venom resistance is unknown. The muscular nicotinic cholinergic receptor (nAChR), targeted by snake α-neurotoxins, has evolved in some venom-resistant mammals to no longer bind these toxins. Through phylogenetic analysis of mammalian nAChR sequences, we show that honey badgers, hedgehogs, and pigs have independently acquired functionally equivalent amino acid replacements in the toxin-binding site of this receptor. These convergent amino acid changes impede toxin binding by introducing a positively charged amino acid in place of an uncharged aromatic residue. In venom-resistant mongooses, different replacements at these same sites are glycosylated, which is thought to disrupt binding through steric effects. Thus, it appears that resistance to snake venom α-neurotoxin has evolved at least four times among mammals through two distinct biochemical mechanisms operating at the same sites on the same receptor.
Copyright © 2015 Elsevier Ltd. All rights reserved.
Copyright © 2015 Elsevier Ltd. All rights reserved.
Additional References
Mutation #2
Presumptive Null
Molecular Type
Aberration Type
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
Trp187Arg + Phe189Leu
Experimental Evidence
| Taxon A | Taxon B | Position | |
|---|---|---|---|
| Codon | - | - | - |
| Amino-acid | Phe | Leu | 189 |
Authors
Drabeck DH; Dean AM; Jansa SA
Abstract
Honey badgers (Mellivora capensis) prey upon and survive bites from venomous snakes (Family: Elapidae), but the molecular basis of their venom resistance is unknown. The muscular nicotinic cholinergic receptor (nAChR), targeted by snake α-neurotoxins, has evolved in some venom-resistant mammals to no longer bind these toxins. Through phylogenetic analysis of mammalian nAChR sequences, we show that honey badgers, hedgehogs, and pigs have independently acquired functionally equivalent amino acid replacements in the toxin-binding site of this receptor. These convergent amino acid changes impede toxin binding by introducing a positively charged amino acid in place of an uncharged aromatic residue. In venom-resistant mongooses, different replacements at these same sites are glycosylated, which is thought to disrupt binding through steric effects. Thus, it appears that resistance to snake venom α-neurotoxin has evolved at least four times among mammals through two distinct biochemical mechanisms operating at the same sites on the same receptor.
Copyright © 2015 Elsevier Ltd. All rights reserved.
Copyright © 2015 Elsevier Ltd. All rights reserved.
Additional References
RELATED GEPHE
Related Genes
No matches found.
Related Haplotypes
EXTERNAL LINKS
COMMENTS
@SeveralMutationsWithEffect ; Parallel changes in a 3rd lineage thought to be venom resistant (pigs)
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