Squamous cell carcinoma antigen 1 is an inhibitor of parasite-derived cysteine proteases.
The physiological significance of the squamous cell carcinoma antigens 1 (SCCA1) and SCCA2, members of the ovalbumin serpin family, remains unresolved. In this study, we examined whether SCCA1 or SCCA2 inhibits protozoa- or helminth-derived cysteine proteases. SCCA1, but not SCCA2, potently inhibited the cysteine protease activities of CPB2.8 from Leishmania mexicana, cruzain from Trypanosoma cruzi, rhodesain from Trypanosoma brucei rhodesience, and cathepsin L2 from Fasciola hepatica. The inhibitory activities of SCCA1 were due to its resistance to cleavage by the cysteine proteases. The findings indicate that induction of cysteine protease inhibitors might be a novel defense mechanism against parasite development.
Kanaji
Sachiko
S
Division of Medical Biochemistry, Department of Biomolecular Sciences, Saga Medical School, 5-1-1 Nabeshima, Saga 849-8501, Japan.
Tanaka
Yoko
Y
Sakata
Yasuhisa
Y
Takeshita
Kohei
K
Arima
Kazuhiko
K
Ohta
Shoichiro
S
Hansell
Elizabeth J
EJ
Caffrey
Conor
C
Mottram
Jeremy C
JC
Lowther
Jonathan
J
Donnelly
Sheila
S
Stack
Colin
C
Kadowaki
Tomoko
T
Yamamoto
Kenji
K
McKerrow
James H
JH
Dalton
John P
JP
Coombs
Graham H
GH
Izuhara
Kenji
K
D000595:Amino Acid Sequence; D000818:Animals; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism; D008969:Molecular Sequence Data; D010271:Parasites / Q000201:enzymology*; D015843:Serpins / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship
D000951:Antigens, Neoplasm; D015853:Cysteine Proteinase Inhibitors; D015843:Serpins; C051072:squamous cell carcinoma-related antigen; D003546:Cysteine Endopeptidases