A human cDNA coding for the Leydig insulin-like peptide (Ley I-L).
cDNA clones for the human Leydig insulin-like peptide (Ley I-L) have been isolated and characterized. The nucleotide sequence of the 743-bp cDNA includes an incomplete 7-bp 5'-noncoding region, an open reading frame of 393 bp, and a 343-bp 3'-noncoding region. By primer extension analysis, the transcription start site was determined as being 14-bp upstream of the translation start site. The underlying gene is expressed in the testis but not in other organs. From the cDNA sequence, it can be deduced that the Ley I-L protein is synthesized as a 131-amino-acid (aa) preproprotein and that it contains a 24-aa signal peptide. Comparison of the pro Ley I-L protein with members of the insulin-like hormone superfamily predicts that the biologically active hormone, after proteolytic processing of the C peptide, consists of a 31-aa long B chain and a 26-aa long A chain, and that it has a molecular weight of 6.25 kDa.
Institut für Humangenetik, Universität Göttingen, Germany.
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Burkhardt
I M
IM
Adham
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Hobohm
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D
Murphy
C
C
Sander
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Engel
D000595:Amino Acid Sequence; D001483:Base Sequence; D018076:DNA, Complementary; D015870:Gene Expression; D006728:Hormones / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D007328:Insulin; D008297:Male; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000378:metabolism*
D018076:DNA, Complementary; D006728:Hormones; D007328:Insulin; C084797:Leydig insulin-like protein; D011506:Proteins