Several tissues of Mirabilis jalapa L. (Nyctaginaceae) were assayed for inhibition of translation by a rabbit reticulocyte lysate (as a signal of ribosome-inactivating activity) and for adenine DNA glycosylase activity, activities that are both due to the presence of a class of enzymes called ribosome-inactivating proteins (RIPs), currently classified as rRNA N-glycosylases (EC 3.2.2.22). These activities were highest in seed; intermediate in flower bud, immature seed, sepal + gynoecium, leaf, and root; and very low in all other tissues. By cation-exchange chromatography, four protein peaks with inhibitory activity on cell-free translation were identified in extracts from seeds, and two proteins were isolated from peaks 1 and 4, all of which have the properties of single-chain type 1 RIP. One is Mirabilis antiviral protein (MAP), so far purified only from roots. The second is a new protein that we propose to call MAP-4. The distribution of MAP and MAP-4 in several tissues was determined with a novel experimental approach based on liquid chromatography/mass spectrometry. The direct enzymatic activity of MAP on several substrates is described here for the first time. MAP depurinated not only rRNA in intact ribosomes, thus inhibiting protein synthesis, but also other polynucleotides such as poly(A), DNA, and tobacco mosaic virus RNA. Autologous DNA was depurinated more extensively than other polynucleotides. Therefore, the enzymatic activity of this protein may be better described as adenine polynucleotide glycosylase activity rather than rRNA N-glycosylase activity. Finally, MAP does not cross-react immunologically with other commonly utilized RIPs.

Bolognesi A., Polito L., Lubelli C., Barbieri L., Parente A., Stirpe F. (2002). Ribosome-inactivating and adenine polynucleotide glycosylase activities in Mirabilis jalapa L. tissues. THE JOURNAL OF BIOLOGICAL CHEMISTRY, 277(16), 13709-13716 [10.1074/jbc.M111514200].

Ribosome-inactivating and adenine polynucleotide glycosylase activities in Mirabilis jalapa L. tissues

Bolognesi A.
;
Polito L.;Lubelli C.;Barbieri L.;Parente A.;Stirpe F.
2002

Abstract

Several tissues of Mirabilis jalapa L. (Nyctaginaceae) were assayed for inhibition of translation by a rabbit reticulocyte lysate (as a signal of ribosome-inactivating activity) and for adenine DNA glycosylase activity, activities that are both due to the presence of a class of enzymes called ribosome-inactivating proteins (RIPs), currently classified as rRNA N-glycosylases (EC 3.2.2.22). These activities were highest in seed; intermediate in flower bud, immature seed, sepal + gynoecium, leaf, and root; and very low in all other tissues. By cation-exchange chromatography, four protein peaks with inhibitory activity on cell-free translation were identified in extracts from seeds, and two proteins were isolated from peaks 1 and 4, all of which have the properties of single-chain type 1 RIP. One is Mirabilis antiviral protein (MAP), so far purified only from roots. The second is a new protein that we propose to call MAP-4. The distribution of MAP and MAP-4 in several tissues was determined with a novel experimental approach based on liquid chromatography/mass spectrometry. The direct enzymatic activity of MAP on several substrates is described here for the first time. MAP depurinated not only rRNA in intact ribosomes, thus inhibiting protein synthesis, but also other polynucleotides such as poly(A), DNA, and tobacco mosaic virus RNA. Autologous DNA was depurinated more extensively than other polynucleotides. Therefore, the enzymatic activity of this protein may be better described as adenine polynucleotide glycosylase activity rather than rRNA N-glycosylase activity. Finally, MAP does not cross-react immunologically with other commonly utilized RIPs.
2002
Bolognesi A., Polito L., Lubelli C., Barbieri L., Parente A., Stirpe F. (2002). Ribosome-inactivating and adenine polynucleotide glycosylase activities in Mirabilis jalapa L. tissues. THE JOURNAL OF BIOLOGICAL CHEMISTRY, 277(16), 13709-13716 [10.1074/jbc.M111514200].
Bolognesi A.; Polito L.; Lubelli C.; Barbieri L.; Parente A.; Stirpe F.
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/959739
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 58
  • ???jsp.display-item.citation.isi??? 55
social impact