RRC ID 73228
Author Tomatsu M, Kondo T, Yoshikawa T, Komeno T, Adachi N, Kawasaki Y, Ikuta A, Tashiro F.
Title An apoptotic inducer, aralin, is a novel type II ribosome-inactivating protein from Aralia elata.
Journal Biol Chem
Abstract We recently found that aralin, a novel cytotoxic protein consisting of two subunits, from Aralia elata selectively induces apoptosis in transformed cells as compared to normal cells. Here we report that aralin is a lectin specific for galactose (Gal) and its derivatives, and possesses RNA N-glycosidase activity as a new type II ribosome-inactivating protein (RIP). The RNA N-glycosidase activity of aralin was detected in cell-free and whole cell systems by the generation of an R-fragment from 28S rRNA. Coinciding with appearance of the R-fragment in aralin-treated cells, significant inhibition of protein synthesis was observed prior to the onset of apoptosis. Aralin-evoked cell death was efficiently repressed by the addition of Gal and its derivatives. Interestingly, melibiose preferentially protected normal cells from apoptosis as compared with transformed cells. Using rhodamine-coupled aralin, the aralin receptor could be clearly detected around the cell surface of transformed cells, but to a lesser extent on normal cells. Receptor binding was suppressed by Gal. These results indicate that aralin is incorporated into cells via its Gal-containing cell surface receptor and induces apoptosis through its RIP activity. Moreover, the expression level and/or structural changes of the aralin receptor may affect the sensitivity toward aralin.
Volume 385(9)
Pages 819-27
Published 2004-9-1
DOI 10.1515/BC.2004.107
PMID 15493877
MeSH Animals Apoptosis / drug effects* Apoptosis / physiology Aralia* Cell Survival / drug effects Cell Survival / physiology Dose-Response Relationship, Drug Lectins / isolation & purification Lectins / pharmacology* Plant Extracts / isolation & purification Plant Extracts / pharmacology Plant Proteins / isolation & purification Plant Proteins / pharmacology Plant Shoots Protein Synthesis Inhibitors / isolation & purification Protein Synthesis Inhibitors / pharmacology* Rats Ribosome Inactivating Proteins, Type 2 Ribosomes / drug effects* Ribosomes / metabolism
IF 3.27
Human and Animal Cells WI-38 VA-13(RCB0251)