title: Molecular cloning and expression of a variant form of hippostasin/KLK11 in prostate.
abstract: BACKGROUND
  Hippostasin is a kallikrein-like serine protease, which has two alternatively spliced isoforms, brain-type and prostate-type. We previously reported alternative expression of hippostasin in prostate cancer cell lines.
  
  
  METHODS
  We studied the expression of a variant-form hippostasin (isoform 3) mRNA by RT-PCR. Localization of the isoform 3 protein was examined by immunohistochemistry. The enzymatic activity of the recombinant protein was measured with synthetic substrates.
  
  
  RESULTS
  A novel isoform of hippostasin contains 25 additional amino acids in the catalytic triad of brain-type hippostasin. Its mRNA was expressed in normal prostate tissue, BPH, and prostate cancer cell lines. The protein was localized in the prostate secretory epithelium. The enzyme activity was similar to that of brain-type hippostasin, which has kallikrein-like activity.
  
  
  CONCLUSIONS
  In this study, we have identified a third isoform of hippostasin, which was designated variant-form (isoform 3). Hippostasin isoform 3 may play a role in the prostate, including reproductive and/or tumorigenic functions.
authors.affiliation: Department of Urology, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto, Japan.
authors.forename: Terukazu
authors.initials: T
authors.lastname: Nakamura
authors.forename: Shinichi
authors.initials: S
authors.lastname: Mitsui
authors.forename: Akira
authors.initials: A
authors.lastname: Okui
authors.forename: Tsuneharu
authors.initials: T
authors.lastname: Miki
authors.forename: Nozomi
authors.initials: N
authors.lastname: Yamaguchi
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D008297:Male; D008969:Molecular Sequence Data; D011467:Prostate / Q000201:enzymology*; D011471:Prostatic Neoplasms; D012333:RNA, Messenger / Q000032:analysis; D012697:Serine Endopeptidases / Q000235:genetics* / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; C114880:trypsin-like serine protease; D012697:Serine Endopeptidases