Evolutionary Analysis of the ErbB Receptor and Ligand Families

摘要: We have compared all available deduced protein sequences of the ErbB family receptors and their ligands. Analysis aligned indicates that there are some differences in specific to invertebrates. In addition, comparison vertebrate suggest a gene duplication event generated two ancestral receptors, ErbB3/ErbB4 precursor ErbB1/ErbB2 precursor. Subsequent duplications these precursors four present mammals. for known ligands suggests segregate into ErbB1 ligands, paralleling evolution receptors; however, it is difficult ascertain any correlation between invertebrate Even though ErbB3 kinase-impaired, significant conservation kinase domain within lineage (human, rat, F. rubripes), suggesting function this other than activity, such as mediating protein–protein interactions involved receptor dimerization and/or activation heterodimerization partner. To date, no ligand ErbB2 has been identified, extracellular domains reveals regions not conserved across mammalian species. These divergence align with shown be proximal amino-terminus carboxyl-terminal region, respectively, bound EGF. Further, one contains an insertion, relative members family, which might affect binding site provide structural basis receptor's apparent inability bind independently.