Molecular cloning of human cathepsin O, a novel endoproteinase and homologue of rabbit OC2.
A 1670-bp cDNA coding for a novel human cysteine protease has been isolated from a monocyte-derived macrophage cDNA library. This cDNA predicts a 329-amino acid preprocathepsin with more than 50% identity to both human cathepsin S and cathepsin L and 94% identity to a rabbit cDNA, termed OC2, recently isolated from osteoclasts. Based on its high homology to OC2, we have named the human enzyme cathepsin O. Cathepsin O mRNA was identified as a single approximately 1.7 kb transcript in cultures of 15-day-old monocyte-derived macrophages, but was not expressed in human monocytes or alveolar macrophages. When transfected into COS-7 cells, cathepsin O displayed potent endoprotease activity against fibrinogen at acid pH. This novel endoprotease may play an important role in extracellular matrix degradation.
Shi
G P
GP
Physiology Program, Harvard School of Public Health, Boston, MA 02115.
Chapman
H A
HA
Bhairi
S M
SM
DeLeeuw
C
C
Reddy
V Y
VY
Weiss
S J
SJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D056657:Cathepsin K; D002403:Cathepsins / Q000235:genetics*; D002460:Cell Line; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000235:genetics*; D018076:DNA, Complementary; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D018076:DNA, Complementary; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C534130:CTSK protein, human; D056657:Cathepsin K; C534179:CTSO protein, human