Evidence for a Stepwise Evolution of the CD3 Family

摘要: The three CD3 components of the TCR complex are encoded as clustered genes in mammals. evolution such a multimeric is likely to occur stepwise. chicken cluster was entirely sequenced, and, contrast mammals, only two were found be physically linked unrelated HZW10 and epithelial V-like Ag flanking both sides cluster. Biochemical analyses immunoprecipitates confirmed presence proteins revealed an essential role for CD3γδ glycosylation during assembly. Functional indicated that TCR/CD3 efficiently down-regulated by phorbol ester treatment, demonstrating integrity CD3γ-like cytoplasmic internalization motif. These data argue stepwise evolution, with major differences structure between mammalian nonmammalian vertebrates setting basis understanding phylogeny proving ancestral nature protein.