|ZFIN ID: ZDB-PUB-060623-23|
Identification of multiple integrin beta1 homologs in zebrafish (Danio rerio)
Mould, A.P., McLeish, J.A., Huxley-Jones, J., Gooonesinghe, A.C., Hurlstone, A.F., Boot-Handford, R.P., and Humphries, M.J.
|Source:||BMC Cell Biology 7: 24 (Journal)|
|Registered Authors:||Mould, Paul|
|PubMed:||16787535 Full text @ BMC Cell Biol.|
Mould, A.P., McLeish, J.A., Huxley-Jones, J., Gooonesinghe, A.C., Hurlstone, A.F., Boot-Handford, R.P., and Humphries, M.J. (2006) Identification of multiple integrin beta1 homologs in zebrafish (Danio rerio). BMC Cell Biology. 7:24.
ABSTRACTABSTRACT: BACKGROUND: Integrins comprise a large family of alpha,beta heterodimeric, transmembrane cell adhesion receptors that mediate diverse essential biological functions. Higher vertebrates possess a single beta1 gene, and the beta1 subunit associates with a large number of alpha subunits to form the major class of extracellular matrix (ECM) receptors. Despite the fact that the zebrafish (Danio rerio) is a rapidly emerging model organism of choice for developmental biology and for models of human disease, little is currently known about beta1 integrin sequences and functions in this organism. RESULTS: Using RT-PCR, complete coding sequences of zebrafish beta1 paralogs were obtained from zebrafish embryos or adult tissues. The results show that zebrafish possess two beta1 paralogs (beta1-1 and beta1-2) that have a high degree of identity to other vertebrate beta1 subunits. In addition, a third, more divergent, beta1 paralog is present (beta1-3), which may have altered ligand-binding properties. Zebrafish also have other divergent beta1-like transcripts, which are C-terminally truncated forms lacking the transmembrane and cytoplasmic domains. Together with beta1-3, these truncated forms comprise a novel group of beta1 paralogs, all of which have a mutation in the ADMIDAS cation-binding site. Phylogenetic and genomic analyses indicate that the duplication that gave rise to beta1-1 and beta1-2 occurred after the divergence of the tetrapod and fish lineages, while a subsequent duplication of the ancestor of beta1-2 may have given rise to beta1-3 and an ancestral truncated paralog. A very recent tandem duplication of the truncated beta1 paralogs appears to have taken place. The different zebrafish beta1 paralogs have varied patterns of temporal expression during development. beta1-1 and beta1-2 are ubiquitously expressed in adult tissues, whereas the other beta1 paralogs generally show more restricted patterns of expression. CONCLUSION: Zebrafish have a large set of integrin beta1 paralogs. beta1-1 and beta1-2 may share the roles of the solitary beta1 subunit found in other vertebrates, whereas beta1-3 and the truncated beta1 paralogs may have acquired novel functions.