Structural and functional analysis of the amphioxus IGFBP gene uncovers ancient origin of IGF-independent functions.

ABSTRACT: IGFs play key roles in regulating vertebrate development, growth, reproduction, and aging. In extracellular fluids, IGFs are bound and regulated by a family of IGF-binding proteins (IGFBPs). Although all known IGFBPs are secreted proteins, some are also found in the nucleus and possess IGF-independent activities. When and how these distinct modes of biological actions have evolved is unknown. In this study, we identified and analyzed an IGFBP gene from amphioxus. Amphioxus shares a common ancestor with the modern vertebrate lineage that dates back to more than 520 million years ago. The amphioxus IGFBP shares all major structural characteristics of vertebrate IGFBPs. Phylogenetic analyses place it in a basal position in the IGFBP lineage. Ligand blot analysis reveals that amphioxus IGFBP d

SUBMITTER: Zhou J 

PROVIDER: S-EPMC3776871 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature