Molecular characterization of iron binding proteins, transferrin and ferritin heavy chain subunit, from the bumblebee Bombus ignitus

Comp Biochem Physiol B Biochem Mol Biol. 2009 Jan;152(1):20-7. doi: 10.1016/j.cbpb.2008.09.082. Epub 2008 Sep 16.

Abstract

Transferrin and ferritin are iron-binding proteins involved in transport and storage of iron as part of iron metabolism. Here, we describe the cDNA cloning and characterization of transferrin (Bi-Tf) and the ferritin heavy chain subunit (Bi-FerHCH), from the bumblebee Bombus ignitus. Bi-Tf cDNA spans 2340 bp and encodes a protein of 706 amino acids and Bi-FerHCH cDNA spans 1393 bp and encodes a protein of 217 amino acids. Comparative analysis revealed that Bi-Tf appears to have residues comprising iron-binding sites in the N-terminal lobe, and Bi-FerHCH contains a 5'UTR iron-responsive element and seven conserved amino acid residues associated with a ferroxidase center. The Bi-Tf and Bi-FerHCH cDNAs were expressed as 79 kDa and 27 kDa polypeptides, respectively, in baculovirus-infected insect Sf9 cells. Northern blot analysis revealed that Bi-Tf exhibits fat body-specific expression and Bi-FerHCH shows ubiquitous expression. The expression profiles of the Bi-Tf and Bi-FerHCH in the fat body of B. ignitus worker bees revealed that Bi-Tf and Bi-FerHCH are differentially induced in a time-dependent manner in a single insect by wounding, bacterial challenge, and iron overload.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bees / chemistry*
  • Bees / genetics
  • Binding Sites
  • Cell Line
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Ferritins / chemistry*
  • Ferritins / genetics
  • Gene Expression Regulation
  • Insecta
  • Iron-Binding Proteins
  • Protein Subunits
  • Response Elements
  • Tissue Distribution
  • Transfection
  • Transferrin / chemistry*
  • Transferrin / genetics

Substances

  • DNA, Complementary
  • Iron-Binding Proteins
  • Protein Subunits
  • Transferrin
  • Ferritins