Chemokine CXC receptor 4: an evolutionary approach
M Sisto1, M A Panaro, A Acquafredda
1Department of Human Anatomy and Histology, University of Bari, Bari, Italy.
Immunopharmacology and Immunotoxicology
|December 28, 2006
Summary
Structural similarities between human 18S ribosomal RNA (rRNA) and the chemokine CXC receptor 4 (CXCR4) gene suggest a potential evolutionary link. These nonrandom alignments indicate the CXCR4 gene may be related to the ancient 18S rRNA gene.
Area of Science:
- Genomics
- Molecular Evolution
- Bioinformatics
Background:
- The human 18S ribosomal RNA (rRNA) gene is highly conserved and ancient.
- The chemokine CXC receptor 4 (CXCR4) gene encodes a G-protein coupled receptor involved in cell signaling.
- Previous analysis indicated structural similarities between human 18S rRNA and formyl peptide receptor 1 mRNA.
Purpose of the Study:
- To investigate structural similarities between the human 18S rRNA gene and the human CXCR4 gene.
- To determine if observed similarities between 18S rRNA and CXCR4 are statistically significant or due to chance.
- To explore potential evolutionary relationships between the 18S rRNA and CXCR4 genes.
Main Methods:
- Identified 7-or-more-base oligonucleotide identities between human 18S rRNA and CXCR4 nucleotide sequences.
- Constructed scatter-plots to visualize the positions of these sequence identities.
- Analyzed the distribution and arrangement of identities (quasialignments) to assess their statistical significance.
Main Results:
- Identified significant nonrandom quasialignments between specific regions of the human 18S rRNA gene and the CXCR4 gene (intron and coding sequence).
- Observed these quasialignments when CXCR4 sequences were shifted approximately 1200 nucleotides relative to 18S rRNA sequences.
- A continuous nonrandom quasialignment of approximately 1600 nucleotides was detected from the CXCR4 intron to its coding sequence.
Conclusions:
- The findings suggest a nonrandom structural relationship between the human 18S rRNA gene and the CXCR4 gene.
- A significant evolutionary relationship between the more recent CXCR4 gene and the ancient 18S rRNA gene is hypothesized.
- These results provide evidence for potential evolutionary origins of the CXCR4 gene from more ancient genetic elements.
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