Induction of a transferrin-like protein by iron deprivation in the marine alga Dunaliella tertiolecta

J.L. Kuo, R. Huang, T.T. Kuo-2000

Bulletin of Marine Science, 67 (2) : 789-797  (from Current Contents)

Abstract :

The roles of iron in the growth and physiology of the marine alga Dunaliella tertiolecta were investigated. Comparison of the electrophoretic profiles of total proteins from cells grown under iron-replete or iron-deficient conditions revealed that the abundance of a 38-kDa protein was markedly increased in cells deprived of iron. Electron microscopy also revealed that cells subjected to iron limitation exhibited substantial chlorosis and a defective photosynthetic apparatus. In addition, immunoblot analysis showed that iron deprivation increased the abundance of a 150-kDa protein that reacts with antibodies to human transferrin. With the use of the polymerase chain reaction and primers based on the nucleotide sequences of a gene for a transferrin-like protein in Dunaliella salina, a 9.5-kb fragment of D. tertiolecta genomic DNA that encodes a homologous protein was isolated and sequenced. The fragment isolated from D. tertiolecta comprises 30 exons and contains an open reading frame of 3825 bp that encodes a protein of 1274 amino acids. The predicted amino acid sequence of the encoded protein shows a high degree of homology to those of various transferrin proteins from other organisms.

(Acad Sinica, Inst Mol Biol, Taipei 115, Taiwan, e-mail of T.T. Kuo: tehkuo@ccvax.sinica.edu.tw)


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