A major human epididymis-specific cDNA encodes a protein with sequence homology to extracellular proteinase inhibitors.
The amino acid sequence of a major human epididymis-specific protein was deduced from the nucleotide sequence of its cloned cDNA. The encoded product showed characteristics of a secretory protein, with a signal peptide followed by a small (approximately 10-kDa), acidic (pI 4.3), and cysteine-rich polypeptide. The positions of half-cysteines suggested that it was a two-domain member of the family of 'four-disulfide core' proteins to which a number of proteinase inhibitors belong. Southern blot analyses of human genomic DNA showed that the transcripts originated from a single copy gene. Northern blot and in situ transcript hybridization specifically localized the HE4 (human epididymis gene product) mRNA to the epithelial cells of the epididymal duct, predominantly within the distal sections. A possible function in sperm maturation as indicated by amino acid similarities to extracellular proteinase inhibitors of genital tract mucous secretions is discussed in the context of its tissue-specific transcription.
Institute for Hormone and Fertility Research, Hamburg, Germany.
C
C
Kirchhoff
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I
Habben
R
R
Ivell
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N
Krull
D000368:Aged; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D004247:DNA / Q000235:genetics*; D030501:Epididymal Secretory Proteins; D004822:Epididymis / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008894:Milk Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D009693:Nucleic Acid Hybridization; D011480:Protease Inhibitors / Q000737:chemistry* / Q000378:metabolism; D021382:Protein Sorting Signals / Q000235:genetics; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D015842:Serine Proteinase Inhibitors / Q000235:genetics; D013735:Testicular Hormones / Q000235:genetics*; D023083:beta-Defensins
C426184:DEFB126 protein, human; D030501:Epididymal Secretory Proteins; D008894:Milk Proteins; D011480:Protease Inhibitors; D021382:Protein Sorting Signals; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D012333:RNA, Messenger; D015842:Serine Proteinase Inhibitors; D013735:Testicular Hormones; D023083:beta-Defensins; C024471:whey acidic proteins; D004247:DNA