Antiviral Activity of Ribosome-Inactivating Proteins

Abstract

Ribosome-inactivating proteins (RIPs) are rRNA N-glycosylases from plants (EC 3.2.2.22) that inactivate ribosomes thus inhibiting protein synthesis. The antiviral properties of RIPs have been investigated for more than four decades. However, interest in these proteins is rising due to the emergence of infectious diseases caused by new viruses and the difficulty in treating viral infections. On the other hand, there is a growing need to control crop diseases without resorting to the use of phytosanitary products which are very harmful to the environment and in this respect, RIPs have been shown as a promising tool that can be used to obtain transgenic plants resistant to viruses. The way in which RIPs exert their antiviral effect continues to be the subject of intense research and several mechanisms of action have been proposed. The purpose of this review is to examine the research studies that deal with this matter, placing special emphasis on the most recent findings.

The Structural Characterization and Antipathogenic Activities of Quinoin, a Type 1 Ribosome-Inactivating Protein from Quinoa Seeds

“…Several type 1 RIPs are known for their antiviral properties against many virus pathogens for plants, animals and bacteria. In light of this, several authors have proposed these enzymes as possible candidates to combat infectious diseases and, in particular, to control crop virus diseases, also considering the lack of specific antiviral products used in the open field [15]. Thus, we investigated the possible antiviral action of quinoin against TNV, which affects numerous cultivated plants.…”

“…To date, the biological role of RIPs is still unknown, although different reports indicate that they may be involved in host defence activities, suggesting that these toxins are functional in conferring a fitness advantage [11]. On the other hand, the interest in these enzymes is due to their potential use for the treatment of several human diseases such as tumours, their employment in the construction of immunotoxins/nanoconstructs to obtain specificity [4,12,13] or in plant biotechnology applications to improve resistance against pathogens [11,14], particularly viruses [15,16]. Some RIPs have also been found in edible plants (e.g., cereals, butternut squash (Cucurbita moschata) and bitter melon (Momordica charantia)) and are therefore eaten by humans [17][18][19], although their toxicity is reduced or eliminated during digestion or by cooking food at high temperatures.…”

Post-Infection Entry Mechanism of Ricin A Chain-Pokeweed Antiviral Proteins (RTA-PAPs) Chimeras is Mediated by Viroporins

“…Plants have evolved numerous proteins capable of fighting off not only viral infections but also bacterial and fungal ones, using direct and indirect mechanisms. Ribosome inactivating proteins (RIPs) are such proteins, and can irreversibly inactive protein synthesis, leading to cell death, upon infection by a foreign pathogen [2]. Interestingly, certain RIPs have been found to have very potent direct activities against various animal and human viruses by inhibiting viral entry, hindering viral cell machinery and depurinating viral RNA/DNA.…”

Plant-derived ribosome-inactivating proteins involved in defense against plant viruses

“…The transgenic approach Arthita Bhattacharjee and Shruti Tiwari contributed equally that cleave the N-glycosidic bond between the adenine No. 4324 and its ribose moiety in the 60S subunit of rat ribosomes or the equivalent one in sensitive ribosomes from other organisms (Citores et al, 2021).…”

“…For many years, RIPs have been found to potentially exhibiting antifungal, antibacterial, and antiviral-mediated defense. Several recent studies have proposed the role of plant-based RIPs in defense against bacteria, fungi, viruses, and insect attacks (Citores et al, 2021;de Virgilio et al, 2010;Fabbrini et al, 2017;Girbés et al, 2004;Hartley & Lord, 2004;Ng et al, 2010;Nielsen & Boston, 2001;Schrot et al, 2015;Stirpe, 2004Stirpe, , 2013Van Damme et al, 2001;Walsh et al, 2013;Zhu et al, 2018). The history of research on plant RIPs, their types, and multiple enzymatic activities are well summarized (Bolognesi et al, 2016;Choudhary et al, 2020;Peumans et al, 2001;Zhu et al, 2018).…”