An N-Terminal Fragment of Yeast Ribosomal Protein L3 Inhibits the Cytotoxicity of Pokeweed Antiviral Protein in Saccharomyces cerevisiae

作者：Di Rong^*; Tumer Nilgun E

来源：Toxins, 2014, 6(4): 1349-1361.

DOI：10.3390/toxins6041349

• ribosomal protein L3
• alpha-sarcin/ricin loop
• pokeweed antiviral protein
• ribosome inactivating protein

We have previously shown that ribosomal protein L3 is required for pokeweed antiviral protein (PAP), a type I ribosome inactivating protein, to bind to ribosomes and depurinate the alpha-sarcin/ricin loop (SRL) in yeast. Co-expression of the N-terminal 99 amino acids of yeast L3 (L3 Delta 99) with PAP in transgenic tobacco plants completely abolished the toxicity of PAP. In this study, we investigated the interaction between PAP and L3 Delta 99 in Saccharomyces cerevisiae. Yeast cells co-transformed with PAP and L3 Delta 99 showed markedly reduced growth inhibition and reduced rRNA depurination by PAP, compared to cells transformed with PAP alone. Co-transformation of yeast with PAP and L3 Delta 21 corresponding to the highly conserved N-terminal 21 amino acids of L3 Delta 99, reduced the cytotoxicity of PAP. PAP mRNA and protein levels were elevated and L3 Delta 99 or L3 Delta 21 mRNA and protein levels were reduced in yeast co-transformed with PAP and L3 Delta 99 or with PAP and L3 Delta 21, respectively. PAP interacted with L3 Delta 21 in yeast cells in vivo and by Biacore analysis in vitro, suggesting that the interaction between L3 Delta 21 and PAP may inhibit PAP-mediated depurination of the SRL, leading to a reduction in the cytotoxicity of PAP.

• 出版日期2014-4
• 单位rutgers