Cinnamomin: a multifunctional type II ribosome-inactivating protein.
Plant ribosome-inactivating proteins (RIPs) are a group of toxic proteins that can irreversibly inactivate ribosomes by specifically removing the conserved adenine base from the "Sarcin/Ricin domain" of the 28S RNA in ribosome. Cinnamomin is a novel type II RIP isolated in our laboratory from the mature seeds of camphor tree. Besides site-specific deadenylation of the A4324 in the Sarcin/Ricin domain of rat ribosome, this protein could also release the adenine base from DNA molecules at multiple sites and from AMP, ADP, dAMP and adenosine. Furthermore, cinnamomin displays cytotoxicity to carcinoma cells and insect larvae by modifying their ribosomal RNA. These functions possessed by cinnamomin shed a new light on the possible application of cinnamomin in the field of immunotoxin design and transgenic reagents. In this review, we introduce the major recent results on cinnamomin obtained in our laboratory, including purification of this protein, characterization of its enzymatic mechanism, structure and function, gene pattern, physiological role and its biological implications in cytotoxicity.
He
Wen-Jun
WJ
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Liu
Wang-Yi
WY
D020418:Algal Proteins; D000595:Amino Acid Sequence; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D027423:Cinnamomum camphora / Q000378:metabolism*; D003545:Cysteine / Q000737:chemistry; D003603:Cytotoxins / Q000494:pharmacology; D007313:Insecta / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011506:Proteins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D054790:Ribosome Inactivating Proteins, Type 2; D012639:Seeds / Q000378:metabolism; D014407:Tumor Cells, Cultured
D020418:Algal Proteins; D000972:Antineoplastic Agents, Phytogenic; D003603:Cytotoxins; D011500:Protein Synthesis Inhibitors; D011506:Proteins; D054790:Ribosome Inactivating Proteins, Type 2; C061930:cinnamomin, Phytophthora cinnamomi; D003545:Cysteine