Cloning, sequencing, characterization, and expressions of divalent metal transporter one in the small intestine of broilers.
Divalent metal transporter 1 (DMT1) is an electrogenic transporter of divalent Mn that is expressed at a high level on the brush-border membrane of enterocytes. This study is the first reported isolation of the 2 full-length cDNA sequences of the small intestinal DMT1 gene of broilers by rapid amplification of cDNA ends. The chicken DMT1 isoform I cDNA was 1,972 bp and contained a 1,695-bp open reading frame encoding a 564-amino acid protein, and the chicken DMT1 isoform II cDNA was 1,775 bp and contained a 1,593-bp open reading frame encoding a 530-amino acid protein. The 2 chicken DMT1 isoform transcripts differed in their 3'-translated regions and untranslated regions. The identities of the amino acid sequence deduced from the full-length cDNA sequence of the chicken DMT1 isoform I with DMT1 not containing the iron-responsive element of the mouse, rat, and human were 82, 82, and 80%, respectively. The identities of the amino acid sequence deduced from the full-length cDNA sequence of the chicken DMT1 isoform II with those of the mouse, rat, and human were 84, 84, and 83%, respectively. Analyses of hydrophobicity, transmembrane region, and signal peptides of DMT1 proteins deduced by nucleotide sequences suggested that chicken DMT1 isoforms are transmembrane proteins with several conserved peptide sequences, such as N-linked glycosylation signals (N-X-S/ T, where X designates any amino acid) and the consensus transport motif. The total mRNA levels of the 2 chicken DMT1 isoforms, the mRNA levels of chicken DMT1 isoform I, and the mRNA levels of chicken DMT1 isoform II in the duodenum and jejunum were higher (P<0.002) than that in the ileum by real-time reverse transcription PCR assay. There was no significant difference (P>0.26) between the duodenum and jejunum for the above 3 indices. The mRNA level of the chicken DMT1 isoform I was higher (P<0.001) than that of the chicken DMT1 isoform II in each small intestinal segment of Mn-deficient broilers.
Bai
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Mineral Nutrition Research Division, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100094, PR China.
Lu
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Luo
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Liu
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B
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D027682:Cation Transport Proteins / Q000096:biosynthesis / Q000235:genetics*; D002645:Chickens / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D057927:Hydrophobic and Hydrophilic Interactions; D007421:Intestine, Small / Q000378:metabolism / Q000502:physiology*; D008297:Male; D008345:Manganese / Q000378:metabolism; D008969:Molecular Sequence Data; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique / Q000662:veterinary; D016415:Sequence Alignment; D000099236:Solute Carrier Family 11, Member 2
D027682:Cation Transport Proteins; D018076:DNA, Complementary; D008345:Manganese; D020033:Protein Isoforms; D012333:RNA, Messenger; D000099236:Solute Carrier Family 11, Member 2