The N-terminal Ricin Propeptide Influences the Fate of Ricin A-chain in Tobacco Protoplasts
نویسندگان
چکیده
منابع مشابه
Ricin B Chain Targeted to the Endoplasmic Reticulum of Tobacco Protoplasts Is Degraded by a CDC48- and Vacuole-independent Mechanism*
The B chain of ricin was expressed and delivered to the endoplasmic reticulum of tobacco protoplasts where it disappeared with time in a manner consistent with degradation. This turnover did not occur in the vacuoles or upon secretion. Indeed, several lines of evidence indicate that, in contrast to the turnover of endoplasmic reticulum-targeted ricin A chain in the cytosol, the bulk of expresse...
متن کاملRNA N-glycosidase activity of ricin A-chain. Mechanism of action of the toxic lectin ricin on eukaryotic ribosomes.
The modification reaction of 28 S rRNA in eukaryotic ribosomes by ricin A-chain was characterized. To examine whether ricin A-chain release any bases from 28 S rRNA, rat liver ribosomes were incubated with a catalytic amount of the toxin, and a fraction containing free bases and nucleosides was prepared from the postribosomal fraction of the reaction mixture by means of ion-exchange column chro...
متن کاملKinetic analysis of choriocarcinoma cell intoxication induced by ricin and ricin A chain immunotoxin.
The kinetics of protein synthesis inhibition was studied in the choriocarcinoma-derived BeWo cell line treated with ricin and an immunotoxin (IT) constructed by linking a specific antibody to the A chain of ricin. The IT was specifically cytotoxic to BeWo and other choriocarcinoma cells. The multistep process underlying this kinetics was explored using two mathematical models where the protein ...
متن کاملReductive activation of ricin and ricin A-chain immunotoxins by protein disulfide isomerase and thioredoxin reductase.
Intracellular activation of ricin and of the ricin A-chain (RTA) immunotoxins requires reduction of their intersubunit disulfide(s). This crucial event is likely to be catalyzed by disulfide oxidoreductases and precedes dislocation of the toxic subunit to the cytosol. We investigated the role of protein disulfide isomerase (EC 5.3.4.1, PDI), thioredoxin (Trx), and thioredoxin reductase (EC 1.8....
متن کاملThe internal propeptide of the ricin precursor carries a sequence-specific determinant for vacuolar sorting.
Ricin is a heterodimeric toxin that accumulates in the storage vacuoles of castor bean (Ricinus communis) endosperm. Proricin is synthesized as a single polypeptide precursor comprising the catalytic A chain and the Gal-binding B chain joined by a 12-amino acid linker propeptide. Upon arrival in the vacuole, the linker is removed. Here, we replicate these events in transfected tobacco (Nicotian...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 2006
ISSN: 0021-9258
DOI: 10.1074/jbc.m602678200