Essential cysteine residues for cyclic ADP-ribose synthesis and hydrolysis by CD38.
We have recently demonstrated that cyclic ADP-ribose (cADPR) serves as a second messenger for glucose-induced insulin secretion (Takasawa, S., Nata, K., Yonekura, H., and Okamoto, H. (1993) Science 259, 370-373) and that human leukocyte antigen CD38 has both ADP-ribosyl cyclase and cADPR hydrolase activities (Takasawa, S., Tohgo, A., Noguchi, N., Koguma, T., Nata, K., Sugimoto, T., Yonekura, H., and Okamoto, H. (1993) J. Biol. Chem. 268, 26052-26054). Although the amino acid sequence of Aplysia ADP-ribosyl cyclase exhibits a high degree of amino acid sequence identity with that of CD38, the Aplysia enzyme shows only ADP-ribosyl cyclase but not cADPR hydrolase. In the present study, we introduced site-directed mutations to CD38 and found that C119K- and/or C201E-CD38 exhibited only ADP-ribosyl cyclase activity. Furthermore, Aplysia ADP-ribosyl cyclase into which we introduced the mutations K95C and E176C, which correspond to residues 119 and 201 of human CD38, exhibited not only ADP-ribosyl cyclase activity but also cADPR hydrolase. These results indicate that cysteine residues 119 and 201 in CD38 have crucial roles in the synthesis and hydrolysis of cADPR.
Department of Biochemistry, Tohoku University School of Medicine, Miyagi, Japan.
A
A
Tohgo
S
S
Takasawa
N
N
Noguchi
T
T
Koguma
K
K
Nata
T
T
Sugimoto
Y
Y
Furuya
H
H
Yonekura
H
H
Okamoto
D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000246:Adenosine Diphosphate Ribose / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D000943:Antigens, Differentiation / Q000378:metabolism*; D001048:Aplysia; D001483:Base Sequence; D036563:Cyclic ADP-Ribose; D003545:Cysteine / Q000378:metabolism*; D018076:DNA, Complementary; D006801:Humans; D006868:Hydrolysis; D008562:Membrane Glycoproteins; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016415:Sequence Alignment
D015703:Antigens, CD; D000943:Antigens, Differentiation; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D036563:Cyclic ADP-Ribose; D000246:Adenosine Diphosphate Ribose; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1; D003545:Cysteine