Molecular characterization of iron binding proteins, transferrin and ferritin heavy chain subunit, from the bumblebee Bombus ignitus.
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.
Wang
Dong
D
College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea.
Kim
Bo Yeon
BY
Lee
Kwang Sik
KS
Yoon
Hyung Joo
HJ
Cui
Zheng
Z
Lu
Wei
W
Jia
Jing Ming
JM
Kim
Doh Hoon
DH
Sohn
Hung Dae
HD
Jin
Byung Rae
BR
D000818:Animals; D001516:Bees / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005293:Ferritins / Q000737:chemistry* / Q000235:genetics; D005786:Gene Expression Regulation; D007313:Insecta; D033862:Iron-Binding Proteins; D021122:Protein Subunits; D020218:Response Elements; D014018:Tissue Distribution; D014162:Transfection; D014168:Transferrin / Q000737:chemistry* / Q000235:genetics
D018076:DNA, Complementary; D033862:Iron-Binding Proteins; D021122:Protein Subunits; D014168:Transferrin; D005293:Ferritins