Table 2.
Revised recommended nomenclature of mammalian ADP-ribosyltransferases.
| ADP-ribosyltransferase (ART) | Description of the clan or superfamily of enzymes that can transfer an ADP-ribose group from NAD+ onto a substrate. It includes pseudo-enzymes |
| ARTD family | Defines one family of ARTs that is characterized by a catalytic domain structure related to diphtheria toxin-like bacterial ARTs. This includes the intracellular mammalian ART proteins. They are named: - PARPx (PARPx is the name of a particular ARTD family member; PARP is a name on its own right and it is proposed to not be used as abbreviation for poly-ADP-ribose-polymerase) - TNKSx (TNKSx is the name of a particular ARTD family member and the abbreviation for tankyrase) The previously defined numbering shall be used (see Table 1 and Fig. 2) |
| ARTC family | Defines one family of ARTs that is characterized by a catalytic domain fold related to cholera toxin-like bacterial ARTs. This includes the extracellular, membrane bound as well as secreted mammalian ART proteins (ecto-ARTs). These protein MARylate substrates, ARTC3 and ARTC4, are thought to be inactive |
| Poly-ARTs | ART superfamily members that have the capacity to iteratively transfer multiple ADP-ribose units onto a substrate, thereby forming PAR chains. Presently, they include the ARTD family members PARP1, PARP2, TNKS1, and TNKS2 |
| Mono-ARTs | ART superfamily members that are restricted to the transfer of one ADP-ribose unit, thereby producing MARylated substrates. This term should be used only when a distinction needs to be made to enzymes that can synthesize PAR. As the majority of ARTs MARylate substrates, the use of mono-ART is not necessary in most cases. This includes the following members of the ARTD family: PARP3, PARP4, PARP6-12, PARP14-16. PARP13 is inactive |
| Poly-ADP-ribose-polymerase/Poly(ADP-ribose)polymerase | We recommend that this term is no longer used. PARP should not be used as abbreviation for poly-ADP-ribose-polymerase but as a name in its own right (i.e., PARPx). Most of these proteins do not synthesize PAR, and those that can form PAR do so in a template-independent manner |
| Poly-PARP/mono-PARP | These terms should no longer be used |