Yeast reporter assay to identify cellular components of ricin toxin A chain trafficking

Björn Becker, Tina Schnöder, Manfred J. Schmitt*

*Corresponding author for this work

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)


RTA, the catalytic A-subunit of the ribosome inactivating A/B toxin ricin, inhibits eukaryotic protein biosynthesis by depurination of 28S rRNA. Although cell surface binding of ricin holotoxin is mainly mediated through its B-subunit (RTB), sole application of RTA is also toxic, albeit to a significantly lower extent, suggesting alternative pathways for toxin uptake and transport. Since ricin toxin trafficking in mammalian cells is still not fully understood, we developed a GFP-based reporter assay in yeast that allows rapid identification of cellular components required for RTA uptake and subsequent transport through a target cell. We hereby show that Ypt6p, Sft2p and GARP-complex components play an important role in RTA transport, while neither the retromer complex nor COPIB vesicles are part of the transport machinery. Analyses of yeast knock-out mutants with chromosomal deletion in genes whose products regulate ADP-ribosylation factor GTPases (Arf-GTPases) and/or retrograde Golgi-to-ER (endoplasmic reticulum) transport identified Sso1p, Snc1p, Rer1p, Sec22p, Erv46p, Gea1p and Glo3p as novel components in RTA transport, suggesting the developed reporter assay as a powerful tool to dissect the multistep processes of host cell intoxication in yeast.

Original languageEnglish
Article number366
Issue number12
Publication statusPublished - 6 Dec 2016
Externally publishedYes


  • Endoplasmic reticulum (ER)
  • Retrograde protein transport
  • Ribosome inactivating protein (RIP)
  • Ricin toxin a chain (RTA)
  • S. cerevisiae
  • Trans-golgi network (TGN)


Dive into the research topics of 'Yeast reporter assay to identify cellular components of ricin toxin A chain trafficking'. Together they form a unique fingerprint.

Cite this