Browse
Submit Data
Databases
API
Help

Dataset Information

30 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Anti-tumor activities and apoptotic mechanism of ribosome-inactivating proteins.

ABSTRACT: Ribosome-inactivating proteins (RIPs) belong to a family of enzymes that attack eukaryotic ribosomes and potently inhibit cellular protein synthesis. RIPs possess several biomedical properties, including anti-viral and anti-tumor activities. Multiple RIPs are known to inhibit tumor cell proliferation through inducing apoptosis in a variety of cancers, such as breast cancer, leukemia/lymphoma, and hepatoma. This review focuses on the anti-tumor activities of RIPs and their apoptotic effects through three closely related pathways: mitochondrial, death receptor, and endoplasmic reticulum pathways.

SUBMITTER: Zeng M

PROVIDER: S-EPMC4593346 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Anti-tumor activities and apoptotic mechanism of ribosome-inactivating proteins.

Zeng Meiqi M Zheng Manyin M Lu Desheng D Wang Jun J Jiang Wenqi W Sha Ou O

Chinese journal of cancer 20150717 8

Ribosome-inactivating proteins (RIPs) belong to a family of enzymes that attack eukaryotic ribosomes and potently inhibit cellular protein synthesis. RIPs possess several biomedical properties, including anti-viral and anti-tumor activities. Multiple RIPs are known to inhibit tumor cell proliferation through inducing apoptosis in a variety of cancers, such as breast cancer, leukemia/lymphoma, and hepatoma. This review focuses on the anti-tumor activities of RIPs and their apoptotic effects throu ...[more]

PMID: 26184404

Similar Datasets

Ribosome-inactivating proteins: from plant defense to tumor attack.

Project description:Ribosome-inactivating proteins (RIPs) are EC3.2.32.22 N-glycosidases that recognize a universally conserved stem-loop structure in 23S/25S/28S rRNA, depurinating a single adenine (A4324 in rat) and irreversibly blocking protein translation, leading finally to cell death of intoxicated mammalian cells. Ricin, the plant RIP prototype that comprises a catalytic A subunit linked to a galactose-binding lectin B subunit to allow cell surface binding and toxin entry in most mammalian cells, shows a potency in the picomolar range. The most promising way to exploit plant RIPs as weapons against cancer cells is either by designing molecules in which the toxic domains are linked to selective tumor targeting domains or directly delivered as suicide genes for cancer gene therapy. Here, we will provide a comprehensive picture of plant RIPs and discuss successful designs and features of chimeric molecules having therapeutic potential.

| S-EPMC3153179 | biostudies-literature

Ribosome Inactivating Proteins from Rosaceae.

Project description:Ribosome-inactivating proteins (RIPs) are widespread among higher plants of different taxonomic orders. In this study, we report on the RIP sequences found in the genome/transcriptome of several important Rosaceae species, including many economically important edible fruits such as apple, pear, peach, apricot, and strawberry. All RIP domains from Rosaceae share high sequence similarity with conserved residues in the catalytic site and the carbohydrate binding sites. The genomes of Malus domestica and Pyrus communis contain both type 1 and type 2 RIP sequences, whereas for Prunus mume, Prunus persica, Pyrus bretschneideri, and Pyrus communis a complex set of type 1 RIP sequences was retrieved. Heterologous expression and purification of the type 1 as well as the type 2 RIP from apple allowed to characterize the biological activity of the proteins. Both RIPs from Malus domestica can inhibit protein synthesis. Furthermore, molecular modelling suggests that RIPs from Rosaceae possess three-dimensional structures that are highly similar to the model proteins and can bind to RIP substrates. Screening of the recombinant type 2 RIP from apple on a glycan array revealed that this type 2 RIP interacts with terminal sialic acid residues. Our data suggest that the RIPs from Rosaceae are biologically active proteins.

| S-EPMC6274481 | biostudies-literature

Ribosome-inactivating and related proteins.

Project description:Ribosome-inactivating proteins (RIPs) are toxins that act as N-glycosidases (EC 3.2.2.22). They are mainly produced by plants and classified as type 1 RIPs and type 2 RIPs. There are also RIPs and RIP related proteins that cannot be grouped into the classical type 1 and type 2 RIPs because of their different sizes, structures or functions. In addition, there is still not a uniform nomenclature or classification existing for RIPs. In this review, we give the current status of all known plant RIPs and we make a suggestion about how to unify those RIPs and RIP related proteins that cannot be classified as type 1 or type 2 RIPs.

| S-EPMC4448163 | biostudies-other

Structures and Ribosomal Interaction of Ribosome-Inactivating Proteins.

Project description:Ribosome-inactivating proteins (RIPs) including ricin, Shiga toxin, and trichosanthin, are RNA N-glycosidases that depurinate a specific adenine residue (A-4324 in rat 28S ribosomal RNA, rRNA) in the conserved ?-sarcin/ricin loop (?-SRL) of rRNA. RIPs are grouped into three types according to the number of subunits and the organization of the precursor sequences. RIPs are two-domain proteins, with the active site located in the cleft between the N- and C-terminal domains. It has been found that the basic surface residues of the RIPs promote rapid and specific targeting to the ribosome and a number of RIPs have been shown to interact with the C-terminal regions of the P proteins of the ribosome. At present, the structural basis for the interaction of trichosanthin and ricin-A chain toward P2 peptide is known. This review surveys the structural features of the representative RIPs and discusses how they approach and interact with the ribosome.

| S-EPMC6273143 | biostudies-literature

Ribosome-inactivating proteins: potent poisons and molecular tools.

Project description:Ribosome-inactivating proteins (RIPs) were first isolated over a century ago and have been shown to be catalytic toxins that irreversibly inactivate protein synthesis. Elucidation of atomic structures and molecular mechanism has revealed these proteins to be a diverse group subdivided into two classes. RIPs have been shown to exhibit RNA N-glycosidase activity and depurinate the 28S rRNA of the eukaryotic 60S ribosomal subunit. In this review, we compare archetypal RIP family members with other potent toxins that abolish protein synthesis: the fungal ribotoxins which directly cleave the 28S rRNA and the newly discovered Burkholderia lethal factor 1 (BLF1). BLF1 presents additional challenges to the current classification system since, like the ribotoxins, it does not possess RNA N-glycosidase activity but does irreversibly inactivate ribosomes. We further discuss whether the RIP classification should be broadened to include toxins achieving irreversible ribosome inactivation with similar turnovers to RIPs, but through different enzymatic mechanisms.

| S-EPMC3925711 | biostudies-literature

Engineering of Ribosome-inactivating Proteins for Improving Pharmacological Properties.

Project description:Ribosome-inactivating proteins (RIPs) are N-glycosidases, which depurinate a specific adenine residue in the conserved ?-sarcin/ricin loop (?-SRL) of rRNA. This loop is important for anchoring elongation factor (EF-G for prokaryote or eEF2 for eukaryote) in mRNA translocation. Translation is inhibited after the attack. RIPs therefore may have been applied for anti-cancer, and anti-virus and other therapeutic applications. The main obstacles of treatment with RIPs include short plasma half-life, non-selective cytotoxicity and antigenicity. This review focuses on the strategies used to improve the pharmacological properties of RIPs on human immunodeficiency virus (HIV) and cancers. Coupling with polyethylene glycol (PEG) increases plasma time and reduces antigenicity. RIPs conjugated with antibodies to form immunotoxins increase the selective toxicity to target cells. The prospects for future development on the engineering of RIPs for improving their pharmacological properties are also discussed.

| S-EPMC7150887 | biostudies-literature

Immunotoxins constructed with ribosome-inactivating proteins and their enhancers: a lethal cocktail with tumor specific efficacy.

Project description:The term ribosome-inactivating protein (RIP) is used to denominate proteins mostly of plant origin, which have N-glycosidase enzymatic activity leading to a complete destruction of the ribosomal function. The discovery of the RIPs was almost a century ago, but their usage has seen transition only in the last four decades. With the advent of antibody therapy, the RIPs have been a subject of extensive research especially in targeted tumor therapies, which is the primary focus of this review. In the present work we enumerate 250 RIPs, which have been identified so far. An attempt has been made to identify all the RIPs that have been used for the construction of immunotoxins, which are conjugates or fusion proteins of an antibody or ligand with a toxin. The data from 1960 onwards is reviewed in this paper and an extensive list of more than 450 immunotoxins is reported. The clinical reach of tumor-targeted toxins has been identified and detailed in the work as well. While there is a lot of potential that RIPs embrace for targeted tumor therapies, the success in preclinical and clinical evaluations has been limited mainly because of their inability to escape the endo/lysosomal degradation. Various strategies that can increase the efficacy and lower the required dose for targeted toxins have been compiled in this article. It is plausible that with the advancements in platform technologies or improved endosomal escape the usage of tumor targeted RIPs would see the daylight of clinical success.

| S-EPMC4296666 | biostudies-literature

Ribosomal RNA N-glycosylase Activity Assay of Ribosome-inactivating Proteins.

Project description:Ribosome-inactivating proteins (RIPs) are enzymes that irreversibly inactivate ribosomes as a consequence of their N-glycosylase (EC 3.2.2.22) activity. The enzyme cleaves the N-glycosidic bond between the adenine No. 4324 from the 28S rRNA and its ribose in rat ribosomes (or the equivalent adenine in sensitive ribosomes from other organisms). This adenine is located in the α-sarcin-ricin loop (SRL) that is crucial for anchoring the elongation factor (EF) G and EF2 on the ribosome during mRNA-tRNA translocation in prokaryotes and eukaryotes, respectively. RIPs have been isolated mainly from plants and examples of these proteins are ricin or Pokeweed Antiviral Protein (PAP). These proteins, either alone or as a part of immunotoxins, are useful tools for cancer therapy. The following protocol describes a method to detect the RNA fragment released when the RIP-treated apurinic RNA from rabbit reticulocyte lysate is incubated in the presence of acid aniline by electrophoresis on polyacrylamide gels. The fragment released (Endo's fragment) is diagnostic of the action of RIPs.

| S-EPMC8376481 | biostudies-literature

Studies on crystal structures, active-centre geometry and depurinating mechanism of two ribosome-inactivating proteins.

Project description:Two ribosome-inactivating proteins, trichosanthin and alpha-momorcharin, have been studied in the forms of complexes with ATP or formycin, by an X-ray-crystallographic method at 1.6-2.0 A (0.16-0.20 nm) resolution. The native alpha-momorcharin had been studied at 2.2 A resolution. Structures of trichosanthin were determined by a multiple isomorphous replacement method. Structures of alpha-momorcharin were determined by a molecular replacement method using refined trichosanthin as the searching model. Small ligands in all these complexes have been recognized and built on the difference in electron density. All these structures have been refined to achieve good results, both in terms of crystallography and of ideal geometry. These two proteins show considerable similarity in their three-dimensional folding and to that of related proteins. On the basis of these structures, detailed geometries of the active centres of these two proteins are described and are compared with those of related proteins. In all complexes the interactions between ligand atoms and protein atoms, including hydrophobic forces, aromatic stacking interactions and hydrogen bonds, are found to be specific towards the adenine base. The relationship between the sequence conservation of ribosome-inactivating proteins and their active-centre geometry was analysed. A depurinating mechanism of ribosome-inactivating proteins is proposed on the basis of these results. The N-7 atom of the substrate base group is proposed to be protonated by an acidic residue in the active centre.

| S-EPMC1135832 | biostudies-other

SMI-Ribosome inactivating protein conjugates selectively inhibit tumor cell growth.

Project description:Cell-targeting conjugates of Saporin 6, a ribosome inactivating protein (RIP), were prepared using the Saporin Ala 157 Cys mutant, a small molecule inhibitor (SMI) of integrins αvβ3/αvβ5, and a potent cytotoxin, auristatin F (AF). The conjugates selectively and potently inhibited proliferation of tumor cells expressing the target integrins. We anticipate that the small molecule-RIP bioconjugate approach can be broadly applied using other small molecule drugs.

| S-EPMC6594371 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data