Identification of glycosphingolipid receptors for pierisin-1, a guanine-specific ADP-ribosylating toxin from the cabbage butterfly.
Pierisin-1, a cytotoxic protein found naturally in the cabbage butterfly, induces apoptosis of mammalian cells. Our recent studies suggest that pierisin-1 consists of an N-terminal ADP-ribosyltransferase domain, and a C-terminal region that binds to receptors on the surfaces of target cells and incorporates the protein into cells. The present study was undertaken to identify receptors for pierisin-1. The cross-linking and cloning experiments suggested that the proteins on cell membrane had no binding ability to pierisin-1. Inhibitory assays of fractionated lipids from human cervical carcinoma HeLa cells, which are highly sensitive to pierisin-1, indicated neutral glycosphingolipids on the cell surface to show receptor activity. Inhibitory assays and TLC immunostaining using anti-pierisin-1 antibodies demonstrated two neutral glycosphingolipids as active components. Analysis of their structures with glycosphingolipid-specific antibodies and negative secondary ion mass spectrometry identified them as globotriaosylceramide (Gb3) and globotetraosylceramide (Gb4). The receptor activities of Gb3 and Gb4 for pierisin-1 were also confirmed with these authentic compounds. Pierisin-1-insensitive mouse melanoma MEB4 cells were found to lack pierisin-1 receptors, including Gb3 and Gb4, but pretreatment of the cells with glycosphingolipid Gb3 or Gb4 enhanced their sensitivity to pierisin-1. Thus, Gb3 and Gb4 were proven to serve as pierisin-1 receptors. The C-terminal region of pierisin-1 consists of possible lectin domains of a ricin B-chain, containing QXW sequences, which are essential for its structural organization. Alteration of QXW by site-directed mutagenesis caused marked reduction of pierisin-1 cytotoxicity. Thus, our results suggest that pierisin-1 binds to Gb3 and Gb4 receptors at the C-terminal region, in a manner similar to ricin, and then exhibits cytotoxicity after incorporation into the cell.
Matsushima-Hibiya
Yuko
Y
Cancer Prevention Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. yhibiya@gan2.ncc.go.jp
Watanabe
Masahiko
M
Hidari
Kazuya I-P
KI
Miyamoto
Daisei
D
Suzuki
Yasuo
Y
Kasama
Takeshi
T
Kasama
Takashi
T
Koyama
Kotaro
K
Sugimura
Takashi
T
Wakabayashi
Keiji
K
D036002:ADP Ribose Transferases; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002080:Butterflies; D002855:Chromatography, Thin Layer; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006028:Glycosphingolipids / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D019476:Insect Proteins / Q000737:chemistry* / Q000378:metabolism*; D037102:Lectins; D013058:Mass Spectrometry; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010743:Phospholipids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D003432:Cross-Linking Reagents; D006028:Glycosphingolipids; D019476:Insect Proteins; D037102:Lectins; D010743:Phospholipids; D011956:Receptors, Cell Surface; C113557:pierisin protein, insect; D036002:ADP Ribose Transferases