Role of melanotransferrin in iron metabolism: studies using targeted gene disruption in vivo.

Melanotransferrin (MTf) or tumor antigen p97 is a transferrin homolog that binds one iron (Fe) atom and has been suggested to play roles in a variety of processes, including Fe metabolism, eosinophil differentiation, and plasminogen activation. Considering the vital role of Fe in many metabolic pathways, such as DNA and heme synthesis, it is important to understand the function of MTf. To define this, a MTf knockout (MTf-/-) mouse was generated through targeted disruption of the MTf gene. The MTf-/- mice were viable and fertile and developed normally, with no morphologic or histologic abnormalities. Assessment of Fe indices, tissue Fe levels, hematology, and serum chemistry parameters demonstrated no differences between MTf-/- and wild-type (MTf+/+) mice, suggesting MTf was not essential for Fe metabolism.