Abstract
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.
Highlights
Because of their N-glycosidase activity, ribosome-inactivating proteins inhibit protein synthesis by cleaving a specific adenine residue (A4324) from the 28S ribosomal RNA of the large 60S subunit of rat ribosomes followed by cell death [1]
There are Ribosome-inactivating proteins (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
Beside the peculiar type 1 RIPs, b-32 and JIP60, there is a certain amount of other proteins that cannot be grouped into the classical type 1 or type 2 RIPs, because of structural and functional differences
Summary
Because of their N-glycosidase activity, ribosome-inactivating proteins inhibit protein synthesis by cleaving a specific adenine residue (A4324) from the 28S ribosomal RNA of the large 60S subunit of rat ribosomes followed by cell death [1]. In some cases, the same term was used to designate different proteins, e.g., the term momordin II was used for a protein from Momordica balsamina as well as for a protein from Momordica charantia or the term MAP was used for a protein (MAP 30) from Momorica charantia and for a protein from Mirabilis jalapa (MAP = Mirabilis antiviral protein) These examples are intended to illustrate that there is still no unambiguous nomenclature for the RIPs. There are ambiguities about the classification of some proteins, whether they are type 2 RIPs or just lectins, because no assay concerning the toxicity was performed or there was no information given about the structure: SGSL from Trichosanthes anguina, TCSL from Trichosanthes cucumerina, TKL-1 from Trichosanthes kirilowii, TDSL from Tichosanthes dioica, and BDA from Bryonia dioica. We focused on RIPs from plants, whereas other RIPs from algae, bacteria, and fungi are not considered further
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.