TY - JOUR
T1 - Phylogenetic shadowing of a histamine-gated chloride channel involved in insect vision
AU - Iovchev, M
AU - Boutanaev, A
AU - Ivanov, I
AU - Wolstenholme, A
AU - Nurminsky, D
AU - Semenov, E
N1 - ID number: ISI:000234767300002
PY - 2006
Y1 - 2006
N2 - A recently identified gene, hlcA (synonym: ort), codes for an ionotrophic histamine receptor Subunit in Drosophila melanogaster, and known hclA mutations lead to defects in the Visual system, neurologic disorders and changed responsiveness to neurotoxins. To investigate whether this novel class of receptors is common across the Insecta, we analysed the genomes of 15 other insect species (Diptera, Hymenoptera, Coleoptera, Lepidoptera) and revealed orthologs of hclA in all of them. The predicted receptor domain of HCLA is extensively conserved (86-100% of identity) among the 16 proteins. Minor changes in the amino acid sequence that includes the putative transmembrane domains (TMs) 1-3 were found in non-drosophilid species only. Substantial amino acid variability was observed in the signal polypeptides, the intracellular loop domains and in TM4, in good accordance with known data on sequence variations in ligand-gated ion channels. Pairwise comparisons revealed three consensus sequences for N-glycosylation, conserved in HCLAs of all species studied, as well as a drosophilid-specific putative phosphorylation site. Real-time PCR analysis demonstrated that hclA-mRNA is abundant in heads of adult Drosophila. However, species- and sex-specific variations of the hclA expression levels were also observed. (C) 2005 Elsevier Ltd. All rights reserved.
AB - A recently identified gene, hlcA (synonym: ort), codes for an ionotrophic histamine receptor Subunit in Drosophila melanogaster, and known hclA mutations lead to defects in the Visual system, neurologic disorders and changed responsiveness to neurotoxins. To investigate whether this novel class of receptors is common across the Insecta, we analysed the genomes of 15 other insect species (Diptera, Hymenoptera, Coleoptera, Lepidoptera) and revealed orthologs of hclA in all of them. The predicted receptor domain of HCLA is extensively conserved (86-100% of identity) among the 16 proteins. Minor changes in the amino acid sequence that includes the putative transmembrane domains (TMs) 1-3 were found in non-drosophilid species only. Substantial amino acid variability was observed in the signal polypeptides, the intracellular loop domains and in TM4, in good accordance with known data on sequence variations in ligand-gated ion channels. Pairwise comparisons revealed three consensus sequences for N-glycosylation, conserved in HCLAs of all species studied, as well as a drosophilid-specific putative phosphorylation site. Real-time PCR analysis demonstrated that hclA-mRNA is abundant in heads of adult Drosophila. However, species- and sex-specific variations of the hclA expression levels were also observed. (C) 2005 Elsevier Ltd. All rights reserved.
U2 - 10.1016/j.ibmb.2005.09.002
DO - 10.1016/j.ibmb.2005.09.002
M3 - Article
VL - 36
SP - 10
EP - 17
JO - Insect Biochemistry and Molecular Biology
JF - Insect Biochemistry and Molecular Biology
SN - 0965-1748
IS - 1
ER -