tRNATrp as cofactor of gelonin, a ribosome‐inactivating protein with RNA‐N‐glycosidase activity features required for the cofactor activity

Brigotti, Maurizio; Carnicelli, Domenica; Alvergna, Paola; Pallanca, Alessandra; Sperti, S; Montanaro, Lucio

doi:10.1080/15216549600201672

Cited by 4 publications

(3 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Brigotti and coworkers have demonstrated that tRNAs affect translational inhibitory activity, with the specificity of the stimulation depending on both the RIP and the particular tRNA. Tritin-S was fairly nonspecific in being stimulated equally by different tRNAs, whereas gelonin was stimulated only by tRNA Trp from mammalian and avian cells and not by other tRNAs or tRNA Trp from yeast (20)(21)(22)(23). Given the variety of assays and assay conditions used for RIP analysis, some differences observed in previous studies may be explained by cofactor requirements.…”

Section: Ribosome Susceptibility To Rip Inactivationmentioning

confidence: 86%

RIBOSOME-INACTIVATINGPROTEINS: A Plant Perspective

Nielsen

Boston

2001

Annu. Rev. Plant. Physiol. Plant. Mol. Biol.

243

180

View full text Add to dashboard Cite

Ribosome-inactivating proteins (RIPs) are toxic N-glycosidases that depurinate the universally conserved alpha-sarcin loop of large rRNAs. This depurination inactivates the ribosome, thereby blocking its further participation in protein synthesis. RIPs are widely distributed among different plant genera and within a variety of different tissues. Recent work has shown that enzymatic activity of at least some RIPs is not limited to site-specific action on the large rRNAs of ribosomes but extends to depurination and even nucleic acid scission of other targets. Characterization of the physiological effects of RIPs on mammalian cells has implicated apoptotic pathways. For plants, RIPs have been linked to defense by antiviral, antifungal, and insecticidal properties demonstrated in vitro and in transgenic plants. How these effects are brought about, however, remains unresolved. At the least, these results, together with others summarized here, point to a complex biological role. With genetic, genomic, molecular, and structural tools now available for integrating different experimental approaches, we should further our understanding of these multifunctional proteins and their physiological functions in plants.

show abstract

Section: Ribosome Susceptibility To Rip Inactivationmentioning

confidence: 86%

RIBOSOME-INACTIVATINGPROTEINS: A Plant Perspective

Nielsen

Boston

2001

Annu. Rev. Plant. Physiol. Plant. Mol. Biol.

243

180

View full text Add to dashboard Cite

show abstract

“…The cofactor requirements of the type 1 RIP gelonin (from Gelonium multiflorum) were studied in some detail. One of the supernatant factors for gelonin was identified as tRNA trp (59,60). Only avian (chicken) and mammalian (beef, rat, and rabbit) tRNAs Trp are active, whereas yeast tRNA Trp is completely devoid of stimulating activity.…”

Section: Enzymatic Regulators Of Ripsmentioning

confidence: 99%

Ribosome‐inactivating proteins from plants: more than RNA N‐glycosidases?

2001

View full text Add to dashboard Cite

Many plants contain proteins that are capable of inactivating ribosomes and accordingly are called ribosome-inactivating proteins or RIPs. These typical plant proteins receive a lot of attention in biological and biomedical research because of their unique biological activities toward animal and human cells. In addition, evidence is accumulating that some RIPs play a role in plant defense and hence can be exploited in plant protection. To understand the mode of action of RIPs and to optimize their medical and therapeutical applications and their use as antiviral compounds in plant protection, intensive efforts have been made to unravel the enzymatic activities of RIPs and provide a structural basis for these activities. Though marked progress has been made during the last decade, the enzymatic activity of RIPs has become a controversial issue because of the concept that RIPs possess, in addition to their classical RNA N-glycosidase and polynucleotide:adenosine glycosidase activity, other unrelated enzymatic activities. Moreover, the presumed novel enzymatic activities, especially those related to diverse nuclease activities, are believed to play an important role in various biological activities of RIPs. However, both the novel enzymatic activities and their presumed involvement in the biological activities of RIPs have been questioned because there is evidence that the activities observed are due to contaminating enzymes. We offer a critical review of the pros and cons of the putative novel enzymatic activities of RIPs. Based on the available data, it is suggested that there is little conclusive evidence in support of the presumed activities and that in the past too little attention has been given to the purity of the RIP preparation. The antiviral activity and mode of action of RIPs in plants are discussed in view of their classical and presumed novel enzymatic activities.

show abstract

“…This "competitor assay" was chosen over an electromobility shift assay due to the experimental problems associated with the high pI of gelonin already reported in Ref. 31. Fig.…”

Section: Figmentioning

confidence: 99%

Gelonin Is an Unusual DNA Glycosylase That Removes Adenine from Single-stranded DNA, Normal Base Pairs and Mismatches

Nicolas

Beggs

Taraschi

2000

Journal of Biological Chemistry

View full text Add to dashboard Cite

We reported that plant ribosome inactivating proteins (RIP) have a unique DNA glycosylase activity that removes adenine from single-stranded DNA (Nicolas, E., Beggs, J. M., Haltiwanger, B. M., and Taraschi, T. F. (1998) J. Biol. Chem. 273, 17216 -17220). In this investigation, we further characterized the interaction of the RIP gelonin with single-stranded oligonucleotides and investigated its activity on double-stranded oligonucleotides. At physiological pH, zinc and ␤-mercaptoethanol stimulated the adenine DNA glycosylase activity of gelonin. Under these conditions, gelonin catalytically removed adenine from single-stranded DNA and, albeit to a lesser extent, from normal base pairs and mismatches in duplex DNA. Also unprecedented was the finding that activity on single-stranded and double-stranded oligonucleotides containing multiple adenines generated unstable products with several abasic sites, producing strand breakage and duplex melting, respectively. The results from competition experiments suggested similar interactions between gelonin's DNA-binding domain and oligonucleotides with and without adenine. A reexamination of the classification of gelonin as a DNA glycosylase/AP lyase using the borohydride trapping assay revealed that gelonin was similar to the DNA glycosylase MutY: both enzymes are monofunctional glycosylases, which are trappable to their DNA substrates. The k cat for the removal of adenine from single-stranded DNA was close to the values observed with multisubstrate DNA glycosylases, suggesting that the activity of RIPs on DNA may be physiologically relevant.

show abstract

tRNATrp as cofactor of gelonin, a ribosome‐inactivating protein with RNA‐N‐glycosidase activity features required for the cofactor activity

Cited by 4 publications

References 12 publications

RIBOSOME-INACTIVATINGPROTEINS: A Plant Perspective

RIBOSOME-INACTIVATINGPROTEINS: A Plant Perspective

Ribosome‐inactivating proteins from plants: more than RNA N‐glycosidases?

Gelonin Is an Unusual DNA Glycosylase That Removes Adenine from Single-stranded DNA, Normal Base Pairs and Mismatches

Contact Info

Product

Resources

About