Functional and phylogenetic characterization of noncanonical vitamin B₁₂-binding proteins in zebrafish suggests involvement in cobalamin transport.

ABSTRACT: In humans, transport of food-derived cobalamin (vitamin B₁₂) from the digestive system into the bloodstream involves three paralogous proteins: transcobalamin (TC), haptocorrin (HC), and intrinsic factor (IF). Each of these proteins contains two domains, an α-domain and a β-domain, which together form a cleft in which cobalamin binds. Zebrafish (Danio rerio) are thought to possess only a single cobalamin transport protein, referred to as Tcn2, which is a transcobalamin homolog. Here, we used CRISPR/Cas9 mutagenesis to create null alleles of tcn2 in zebrafish. Fish homozygous for tcn2-null alleles were viable and exhibited no obvious developmentally or behaviorally abnormal phenotypes. For this reason, we hypothesized that previously unidentified cobalamin-ca

SUBMITTER: Benoit CR 

PROVIDER: S-EPMC6231144 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature