Limits...
Bovine CD14 gene characterization and relationship between polymorphisms and surface expression on monocytes and polymorphonuclear neutrophils.

Ibeagha-Awemu EM, Lee JW, Ibeagha AE, Zhao X - BMC Genet. (2008)

Bottom Line: The study has provided information on sequence variations within the CD14 gene and proteins of cattle.Further observations involving a larger sample size are required to validate our findings.The computational analysis on the promoter and comparative analysis with other species has revealed regions of regulatory element motifs that may indicate important regulatory effects on the gene.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Animal Science, McGill University, Ste-Anne-de-Bellevue, Quebec H9X 3V9, Canada. eveline.ibeagha-awemu@mcgill.ca

ABSTRACT

Background: CD14 is an important player in host innate immunity in that it confers lipopolysaccharide sensitivity to cell types like neutrophils, monocytes and macrophages. The study was aimed at characterizing the CD14 gene of cattle for sequence variations and to determine the effect of variations on the expression of the protein on the surfaces of monocytes and neutrophils in healthy dairy cows.

Results: Five SNPs were identified: two within the coding regions (g.A1908G and g.A2318G, numbering is according to GenBank No. EU148609), one in the 5' (g.C1291T) and two in the 3' (g.A2601G and g.G2621T) untranslated regions. SNP 1908 changes amino acid 175 of the protein (p.Asn175Asp, numbering is according to GenBank No. ABV68569), while SNP 2318 involves a synonymous codon change. Coding region SNPs characterized three gene alleles A (GenBank No. EU148609), A1 (GenBank No. EU148610) and B (GenBank No. EU148611) and two deduced protein variants A (ABV68569 and ABV68570) and B (ABV68571). Protein variant A is more common in the breeds analyzed. All SNPs gave rise to 3 haplotypes for the breeds. SNP genotype 1908AG was significantly (P<0.01) associated with a higher percentage of neutrophils expressing more CD14 molecules on their surfaces. The promoter region contains several transcription factor binding sites, including multiple AP-1 and SP1 sites and there is a high conservation of amino acid residues between the proteins of closely related species.

Conclusion: The study has provided information on sequence variations within the CD14 gene and proteins of cattle. The SNP responsible for an amino acid exchange may play an important role in the expression of CD14 on the surfaces of neutrophils. Further observations involving a larger sample size are required to validate our findings. Our SNP and association analyses have provided baseline information that may be used at defining the role of CD14 in mediating bacterial infections. The computational analysis on the promoter and comparative analysis with other species has revealed regions of regulatory element motifs that may indicate important regulatory effects on the gene.

Show MeSH

Related in: MedlinePlus

A Neighbor-joining dendrogram of the phylogenetic relations among the CD14 proteins of cattle, buffalo, goat, sheep, pig, human, mouse and rat. Species common names are preceded by their GenBank numbers. The degree of amino acid conservation between the bovine proteins and other species is represented in percentages. On the nodes are percent bootstrap values.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2536669&req=5

Figure 4: A Neighbor-joining dendrogram of the phylogenetic relations among the CD14 proteins of cattle, buffalo, goat, sheep, pig, human, mouse and rat. Species common names are preceded by their GenBank numbers. The degree of amino acid conservation between the bovine proteins and other species is represented in percentages. On the nodes are percent bootstrap values.

Mentions: Further, we checked the degree of conservation between the CD14 proteins of cattle with those of different species. Protein sequences compared were those deduced in this work, variants A (ABV68569) and B (ABV68571), other published bovine sequences UniProt: BAA21517, AAD32215 and NP_776433, protein sequences of buffalo (ABE68724), goat (ABE68725), sheep (NP_001070677), pig (AAY98033), mouse (CAA32166), rat (NP_068512) and human variant 1 (NP_001035110) and 2 (NP_000582). The analysis revealed extensive conservations in the amino acid composition and structure. For the bovine proteins, the sequence of ABV68569 is the same as BAA21517 while AAD32215 and NP_776433 differed from ABV68569 by having amino acid 209 changed from Ser to Thr. This indicates the presence of a further CD14 protein variant in cattle here named C. Furthermore, the amino acids of the CD14 proteins of buffalo, sheep and goat shared high conservation rates of 97.05%, 95.17%, and 87.40% respectively, with the bovine ABV68569, followed by pig (76.94%) (Figure 4). The rate of amino acid conservation of bovine A variant was less with the human (72.39%), mouse (61.66%) and rat (60.59%) proteins. While bovine, buffalo, goat, sheep and pig proteins are made up of 373 amino acids, the human protein has two more, and the rat and mouse have one more and seven less animo acids, respectively. The signal peptide, made up of the first 20 amino acids, was highly conserved (only one amino acid difference, 14Ser to Pro) between the bovine and buffalo/goat/sheep proteins. The difference between cattle and the pig was 4 amino acids while being highly diverged with human, mouse and rat (7 to 12 amino acid differences). These relationships were further represented phylogenetically (Figure 4). As depicted in Figure 4, three main groups were evident; the rat and mouse proteins in group one (bootstrap value 100), the human proteins in another group (bootstrap value 100) while members of the Artiodactyla order (bovine, buffalo, goat, sheep) and pig formed a group of their own (bootstrap value 99). In the third group, the pig formed an outcrop of its own, while a closer relationship was visible between cattle and buffalo on the one hand (bootstrap value 72) and, goat and sheep on the other hand (bootstrap value 78).


Bovine CD14 gene characterization and relationship between polymorphisms and surface expression on monocytes and polymorphonuclear neutrophils.

Ibeagha-Awemu EM, Lee JW, Ibeagha AE, Zhao X - BMC Genet. (2008)

A Neighbor-joining dendrogram of the phylogenetic relations among the CD14 proteins of cattle, buffalo, goat, sheep, pig, human, mouse and rat. Species common names are preceded by their GenBank numbers. The degree of amino acid conservation between the bovine proteins and other species is represented in percentages. On the nodes are percent bootstrap values.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2536669&req=5

Figure 4: A Neighbor-joining dendrogram of the phylogenetic relations among the CD14 proteins of cattle, buffalo, goat, sheep, pig, human, mouse and rat. Species common names are preceded by their GenBank numbers. The degree of amino acid conservation between the bovine proteins and other species is represented in percentages. On the nodes are percent bootstrap values.
Mentions: Further, we checked the degree of conservation between the CD14 proteins of cattle with those of different species. Protein sequences compared were those deduced in this work, variants A (ABV68569) and B (ABV68571), other published bovine sequences UniProt: BAA21517, AAD32215 and NP_776433, protein sequences of buffalo (ABE68724), goat (ABE68725), sheep (NP_001070677), pig (AAY98033), mouse (CAA32166), rat (NP_068512) and human variant 1 (NP_001035110) and 2 (NP_000582). The analysis revealed extensive conservations in the amino acid composition and structure. For the bovine proteins, the sequence of ABV68569 is the same as BAA21517 while AAD32215 and NP_776433 differed from ABV68569 by having amino acid 209 changed from Ser to Thr. This indicates the presence of a further CD14 protein variant in cattle here named C. Furthermore, the amino acids of the CD14 proteins of buffalo, sheep and goat shared high conservation rates of 97.05%, 95.17%, and 87.40% respectively, with the bovine ABV68569, followed by pig (76.94%) (Figure 4). The rate of amino acid conservation of bovine A variant was less with the human (72.39%), mouse (61.66%) and rat (60.59%) proteins. While bovine, buffalo, goat, sheep and pig proteins are made up of 373 amino acids, the human protein has two more, and the rat and mouse have one more and seven less animo acids, respectively. The signal peptide, made up of the first 20 amino acids, was highly conserved (only one amino acid difference, 14Ser to Pro) between the bovine and buffalo/goat/sheep proteins. The difference between cattle and the pig was 4 amino acids while being highly diverged with human, mouse and rat (7 to 12 amino acid differences). These relationships were further represented phylogenetically (Figure 4). As depicted in Figure 4, three main groups were evident; the rat and mouse proteins in group one (bootstrap value 100), the human proteins in another group (bootstrap value 100) while members of the Artiodactyla order (bovine, buffalo, goat, sheep) and pig formed a group of their own (bootstrap value 99). In the third group, the pig formed an outcrop of its own, while a closer relationship was visible between cattle and buffalo on the one hand (bootstrap value 72) and, goat and sheep on the other hand (bootstrap value 78).

Bottom Line: The study has provided information on sequence variations within the CD14 gene and proteins of cattle.Further observations involving a larger sample size are required to validate our findings.The computational analysis on the promoter and comparative analysis with other species has revealed regions of regulatory element motifs that may indicate important regulatory effects on the gene.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Animal Science, McGill University, Ste-Anne-de-Bellevue, Quebec H9X 3V9, Canada. eveline.ibeagha-awemu@mcgill.ca

ABSTRACT

Background: CD14 is an important player in host innate immunity in that it confers lipopolysaccharide sensitivity to cell types like neutrophils, monocytes and macrophages. The study was aimed at characterizing the CD14 gene of cattle for sequence variations and to determine the effect of variations on the expression of the protein on the surfaces of monocytes and neutrophils in healthy dairy cows.

Results: Five SNPs were identified: two within the coding regions (g.A1908G and g.A2318G, numbering is according to GenBank No. EU148609), one in the 5' (g.C1291T) and two in the 3' (g.A2601G and g.G2621T) untranslated regions. SNP 1908 changes amino acid 175 of the protein (p.Asn175Asp, numbering is according to GenBank No. ABV68569), while SNP 2318 involves a synonymous codon change. Coding region SNPs characterized three gene alleles A (GenBank No. EU148609), A1 (GenBank No. EU148610) and B (GenBank No. EU148611) and two deduced protein variants A (ABV68569 and ABV68570) and B (ABV68571). Protein variant A is more common in the breeds analyzed. All SNPs gave rise to 3 haplotypes for the breeds. SNP genotype 1908AG was significantly (P<0.01) associated with a higher percentage of neutrophils expressing more CD14 molecules on their surfaces. The promoter region contains several transcription factor binding sites, including multiple AP-1 and SP1 sites and there is a high conservation of amino acid residues between the proteins of closely related species.

Conclusion: The study has provided information on sequence variations within the CD14 gene and proteins of cattle. The SNP responsible for an amino acid exchange may play an important role in the expression of CD14 on the surfaces of neutrophils. Further observations involving a larger sample size are required to validate our findings. Our SNP and association analyses have provided baseline information that may be used at defining the role of CD14 in mediating bacterial infections. The computational analysis on the promoter and comparative analysis with other species has revealed regions of regulatory element motifs that may indicate important regulatory effects on the gene.

Show MeSH
Related in: MedlinePlus