Characterization of the First Nonmammalian T2 Cytokine Gene Cluster: The Cluster Contains Functional Single-Copy Genes for IL-3, IL-4, IL-13, and GM-CSF, a Gene for IL-5 That Appears to Be a Pseudogene, and a Gene Encoding Another Cytokinelike Transcript, KK34
Autor: | James C. Kaufman, Stuart Avery, Virgil E.J.C. Schijns, Winfried D.J. Degen, John R. Young, Lisa Rothwell, Peter K. Kaiser |
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Rok vydání: | 2004 |
Předmět: |
Untranslated region
Chromosomes Artificial Bacterial DNA Complementary Pseudogene Molecular Sequence Data Immunology Biology Mice Species Specificity Sequence Homology Nucleic Acid Virology Gene cluster Gene duplication Animals Humans Amino Acid Sequence Promoter Regions Genetic Gene Synteny Genetics Interleukin-13 Base Sequence Sequence Homology Amino Acid Contig Granulocyte-Macrophage Colony-Stimulating Factor Cell Biology Molecular biology Regulatory sequence Multigene Family Cytokines Interleukin-3 Interleukin-4 Interleukin-5 Chickens Pseudogenes |
Zdroj: | Journal of Interferon & Cytokine Research. 24:600-610 |
ISSN: | 1557-7465 1079-9907 |
Popis: | A genomics approach based on the conservation of synteny was used to develop a bacterial artificial chromosome (BAC) contig across the chicken T2 cytokine gene cluster. Sequencing of representative BACs showed that the chicken genome encodes genes for the homologs of mammalian interleukin-3 (IL-3), IL-4, IL-5, IL-13, and granulocyte-macrophage colony-stimulating factor (GM-CSF). These sequences represent the first T2 cytokines found outside of mammals, and their location demonstrates that the T2 cluster is ancient (at least 300 million years old). Four of these genes (IL-3, IL-4, IL-13, and GM-CSF) are expressed at the mRNA level and can be expressed as recombinant protein. In contrast to the other four genes, the chicken IL-5 (ChIL-5) gene we sequenced lacks a recognizable promoter and regulatory sequences in the predicted 3'-untranslated region (3'-UTR). Further, there is no evidence for its expression at the mRNA level. We, therefore, hypothesize that it is a pseudogene. Genomic analysis revealed that a recently characterized cytokinelike transcript, KK34, not identified in our initial analysis of the BAC sequence, is also encoded in this cluster. This gene may represent a duplication of an ancestral IL-5 gene and may encode the functional homolog of IL-5 in the chicken. |
Databáze: | OpenAIRE |
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