ADP-ribosylation is a widespread post-translational modification regulating a vast array of cellular processes, ranging from DNA-damage repair, transcription and cell-cycle progression, to viral infection and stress response. Many of these functions are mediated by enzymes of the poly-ADP-ribosyl polymerase (PARP) family; the mechanism of action and substrates of the different PARPs remain however to be fully elucidated. In order to identify the specific substrates of PARP activities, a fundamental step to elucidate their physiological function, we selected PARP12 that based on our initial investigation showed a robust catalytic activity. The main role reported so far for PARP12 refers to mRNA regulation during stress response. Here, we present a new function of PARP12 under non-stressing conditions, showing the pathways in which this enzyme is involved through the identification of its substrates. We show that PARP12 is able to interact and modify Golgin-97, a trans-Golgi-localised protein that is involved in the maintenance of the Golgi architecture and in the regulation of vesicular traffic. Further, we demonstrate that PARP12 specifically controls Golgin-97 mediated trafficking routes, pointing at a novel role of this post-translational modification in the regulation of intracellular membrane traffic. Bioinformatics and mutagenesis approaches have been undertaken to further dissect the molecular mechanism at the base of this pathway.
PARP12-dependent mono-ADP-ribosylation of Golgin-97 is involved in the control of intracellular membrane traffic
2017
Abstract
ADP-ribosylation is a widespread post-translational modification regulating a vast array of cellular processes, ranging from DNA-damage repair, transcription and cell-cycle progression, to viral infection and stress response. Many of these functions are mediated by enzymes of the poly-ADP-ribosyl polymerase (PARP) family; the mechanism of action and substrates of the different PARPs remain however to be fully elucidated. In order to identify the specific substrates of PARP activities, a fundamental step to elucidate their physiological function, we selected PARP12 that based on our initial investigation showed a robust catalytic activity. The main role reported so far for PARP12 refers to mRNA regulation during stress response. Here, we present a new function of PARP12 under non-stressing conditions, showing the pathways in which this enzyme is involved through the identification of its substrates. We show that PARP12 is able to interact and modify Golgin-97, a trans-Golgi-localised protein that is involved in the maintenance of the Golgi architecture and in the regulation of vesicular traffic. Further, we demonstrate that PARP12 specifically controls Golgin-97 mediated trafficking routes, pointing at a novel role of this post-translational modification in the regulation of intracellular membrane traffic. Bioinformatics and mutagenesis approaches have been undertaken to further dissect the molecular mechanism at the base of this pathway.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
