Molecular cloning of human cDNA for cathepsin K: novel cysteine proteinase predominantly expressed in bone.
We have previously cloned a rabbit cDNA clone (OC-2) from an osteoclast cDNA library by the differential screening. OC-2 was found to encode a novel cysteine proteinase, tentatively called cathepsin K, which is predominantly expressed in osteoclasts. By use of a rabbit OC-2 fragment as a probe, its human counterpart was cloned from a cDNA library of osteoarthritic hip bone. The cloned human cDNA (hOC-2) encoded a protein of 329 amino acid residues and its deduced amino acid sequence showed 94% homology to rabbit cathepsin K. Multiple alignment of amino acid sequences of human cathepsins B, H, L, S and K showed the highest homology of cathepsin K to cathepsin S 48%. Northern blot analysis showed that cathepsin K mRNA is expressed at high levels in some osteoarthritic hip bones and at a very high level in osteoclastoma compared to very low levels in other tissues. These results suggest that cathepsin K is closely involved in human osteoclastic bone resorption.
Inaoka
T
T
International Research Laboratories, Ciba-Geigy Japan Ltd., Takarazuka.
Bilbe
G
G
Ishibashi
O
O
Tezuka
K
K
Kumegawa
M
M
Kokubo
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001842:Bone and Bones / Q000201:enzymology*; D056657:Cathepsin K; D002403:Cathepsins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D003001:Cloning, Molecular; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000378:metabolism; D015870:Gene Expression; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010003:Osteoarthritis / Q000201:enzymology; D010006:Osteoblasts / Q000201:enzymology*; D012333:RNA, Messenger / Q000096:biosynthesis; D011817:Rabbits; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D012333:RNA, Messenger; D002403:Cathepsins; C534130:CTSK protein, human; D056657:Cathepsin K