The cytotoxic activity of ribosome-inactivating protein saporin-6 is attributed to its rRNA N-glycosidase and internucleosomal DNA fragmentation activities.

The Cytotoxic Activity of Ribosome-inactivating Protein Saporin-6 Is Attributed to Its rRNA N-Glycosidase and Internucleosomal DNA

Saporin-6 produced by the plant Saponaria officinalis belongs to the family of single chain ribosome-inactivating proteins. It potently inhibits protein synthesis in eukaryotic cells, by cleaving the N-glycosidic bond of a specific adenine in 28 S rRNA, which results in the cell death. Saporin-6 has also been shown to be active on DNA and induces apoptosis. In the current study, we have investi...

The cytotoxic activity of ribosome-inactivating protein saporin-6 is attributed to rRNA N-glycosidase and internucleosomal DNA fragmentation

Cytotoxicity of ribosome-inactivating protein saporin is not mediated through alpha2-macroglobulin receptor.

Saporin is a single chain ribosome-inactivating protein produced by the plant Saponaria officinalis. Several isoforms of saporin have been isolated from various parts of the plant. In the present study recombinant saporin isoforms 5 and 6 were produced in Escherichia coli. Saporin-6 was found to be more active than saporin-5 in its N-glycosidase, cytotoxic, and genomic DNA fragmentation activit...

The differential catalytic activity of ribosome-inactivating proteins saporin 5 and 6 is due to a single substitution at position 162.

Saporin, a type I ribosome-inactivating protein produced by the soapwort plant Saponaria officinalis belongs to a multigene family that encodes its several isoforms. The saporin seed isoform 6 has significantly higher N-glycosidase and cytotoxic activities compared with the seed isoform 5, although the two have identical active sites. In the present study, we have investigated the contribution ...

Polynucleotide: adenosine glycosidase activity of saporin-L1: effect on DNA, RNA and poly(A).

The ribosome-inactivating proteins (RIPs) are a family of plant enzymes for which a unique activity has been determined: rRNA N-glycosidase, which removes adenine at a specific universally conserved position (A4324 in the case of rat ribosomes). Here we report that saporin-L1, a RIP from the leaves of Saponaria officinalis, recognizes other substrates, including RNAs from different sources, DNA...