title: Purification and molecular cloning of a DNA ADP-ribosylating protein, CARP-1, from the edible clam Meretrix lamarckii.
abstract: The cabbage butterflies Pieris rapae and Pieris brassicae have unique enzymes, named pierisin-1 and -2, respectively, that catalyze the ADP-ribosylation of guanine residues of DNA, which has been linked with induction of apoptosis and mutation in mammalian cell lines. In the present study, we identified ADP-ribosylation activity targeting DNA in six kinds of edible clam. Similar to our observations with pierisin-1 and -2, crude extracts from the clams Meretrix lamarckii, Ruditapes philippinarum, and Corbicula japonica incubated with calf thymus DNA and beta-NAD resulted in production of N(2)-(ADP-ribos-1-yl)-2'-deoxyguanosine. The DNA ADP-ribosylating protein in the hard clam M. lamarckii, designated as CARP-1, was purified by column chromatography, and its cDNA was cloned. The cDNA encodes a 182-aa protein with a calculated molecular mass of 20,332. The protein synthesized in vitro from the cDNA in a reticulocyte lysate exhibited the same ADP-ribosylating activity as that of purified CARP-1. Neither the nucleotide nor the deduced amino acid sequence of CARP-1 showed homology with pierisin-1 or -2. However, a glutamic acid residue (E128) at the putative NAD-binding site, conserved in all ADP-ribosyltransferases, was found in CARP-1, and replacement of aspartic acid for this glutamic acid resulted in loss of almost all ADP-ribosylating activity. CARP-1 in the culture medium showed no cytotoxicity against HeLa and TMK-1 cells; however, introduction of this protein by electroporation induced apoptosis in these cells. The finding of clam ADP-ribosylating protein targeting guanine residues in DNA could offer new insights into the biological significance of ADP-ribosylation of DNA.
authors.affiliation: Cancer Prevention Basic Research Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nakano
authors.forename: Yuko
authors.initials: Y
authors.lastname: Matsushima-Hibiya
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Shigeki
authors.initials: S
authors.lastname: Enomoto
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Yukari
authors.initials: Y
authors.lastname: Totsuka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugimura
authors.forename: Keiji
authors.initials: K
authors.lastname: Wakabayashi
mesh_terms: D036002:ADP Ribose Transferases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D049872:Bivalvia / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D015870:Gene Expression; D008969:Molecular Sequence Data
chemical_list: D004247:DNA; C427203:calf thymus DNA; D036002:ADP Ribose Transferases