PARP16/ARTD15 Is a Novel Endoplasmic-Reticulum-Associated Mono-ADP-Ribosyltransferase That Interacts with, and Modifies Karyopherin-ß1

Abstract

BackgroundProtein mono-ADP-ribosylation is a reversible post-translational modification that modulates the function of target proteins. The enzymes that catalyze this reaction in mammalian cells are either bacterial pathogenic toxins or endogenous cellular ADP-ribosyltransferases. The latter include members of three different families of proteins: the well characterized arginine-specific ecto-enzymes ARTCs, two sirtuins and, more recently, novel members of the poly(ADP-ribose) polymerase (PARP/ARTD) family that have been suggested to act as cellular mono-ADP-ribosyltransferases. Here, we report on the characterisation of human ARTD15, the only known ARTD family member with a putative C-terminal transmembrane domain.Methodology/Principal FindingsImmunofluorescence and electron microscopy were performed to characterise the sub-cellular localisation of ARTD15, which was found to be associated with membranes of the nuclear envelope and endoplasmic reticulum. The orientation of ARTD15 was determined using protease protection assay, and is shown to be a tail-anchored protein with a cytosolic catalytic domain. Importantly, by combining immunoprecipitation with mass spectrometry and using cell lysates from cells over-expressing FLAG-ARTD15, we have identified karyopherin-ß1, a component of the nuclear trafficking machinery, as a molecular partner of ARTD15. Finally, we demonstrate that ARTD15 is a mono-ADP-ribosyltransferase able to induce the ADP-ribosylation of karyopherin-ß1, thus defining the first substrate for this enzyme.Conclusions/SignificanceOur data reveal that ARTD15 is a novel ADP-ribosyltransferase enzyme with a new intracellular location. Finally, the identification of karyopherin-ß1 as a target of ARTD15-mediated ADP-ribosylation, hints at a novel regulatory mechanism of karyopherin-ß1 functions.

Structures and Mechanisms of Enzymes Employed in the Synthesis and Degradation of PARP-Dependent Protein ADP-Ribosylation

“…The latter domain, which has a predominantly a-helical structure, binds the hydrophobic patch in the beta sheet of ubiquitin and allows PARP10 to regulate NF-kB signaling via the interaction with K63 polyubiquitin chains . PARP16 was recently shown to be associated with ER and to play a role in unfolded protein response (Di Paola et al, 2012;Jwa and Chang, 2012); however, no structural data are available for the domains outside the catalytic domain of this PARP . Although very little is known about PARPs 6, 8, and 11, a recent study of the WWE domain present in PARP11 shows that it preferentially binds the terminal ADP-ribose groups instead of PAR.…”

The intrinsic disorder alphabet. III. Dual personality of serine

“…In agreement with this hypothesis, it has been established that an endoplasmic-reticulum-associated mono-ADP-ribosyltransferase PARP16/ARTD15 interacts with karyopherin-b1, and modifies neither acidic nor basic residues, but threonine or serine residues of this protein. 254,255 O-palmitoylation Palmitoylation is the covalent attachment of a palmitoyl group derived from the palmitic acid (which is a 16-carbon fatty acid) to cysteine (S-palmitoylation), serine or threonine residues (O-palmitoylation). This type of PTM is rather common among various cellular signaling proteins, since it mediates the interaction of proteins with membranes and other proteins and can control the biological activity of a protein.…”

ADP-ribose polymer depletion leads to nuclear Ctcf re-localization and chromatin rearrangement

“…We have recently provided evidence of a close link between ADP ribosylation and intracellular trafficking [46]. Karyopherin-β1/importin-β1, which plays a key role in the shuttling of proteins between the cytosol and the nucleus through the NPC, is ADP ribosylated by the ER (endoplasmic reticulum)-resident ADPribosyltransferase ARTD15 [46].…”