The mono-ADP-ribosyltransferase ARTD10 regulates the voltage-gated K+ channel Kv1.1 through protein kinase C delta

Priyanka Tripathi,Stefan Gründer,Azadeh Nikouee,Bernhard Lüscher,Carsten Bolm,Arno Classen,Dominik Wiemuth,Björn H Falkenburger,Daniel Komnig,Patricia Korn,Yuemin Tian

doi:10.1186/s12915-020-00878-1

Priyanka Tripathi, Stefan Gründer + Show 9 more

Open Access

https://doi.org/10.1186/s12915-020-00878-1

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Abstract

BackgroundADP-ribosylation is a ubiquitous post-translational modification that involves both mono- and poly-ADP-ribosylation. ARTD10, also known as PARP10, mediates mono-ADP-ribosylation (MARylation) of substrate proteins. A previous screen identified protein kinase C delta (PKCδ) as a potential ARTD10 substrate, among several other kinases. The voltage-gated K+ channel Kv1.1 constitutes one of the dominant Kv channels in neurons of the central nervous system and the inactivation properties of Kv1.1 are modulated by PKC. In this study, we addressed the role of ARTD10-PKCδ as a regulator of Kv1.1.ResultsWe found that ARTD10 inhibited PKCδ, which increased Kv1.1 current amplitude and the proportion of the inactivating current component in HeLa cells, indicating that ARTD10 regulates Kv1.1 in living cells. An inhibitor of ARTD10, OUL35, significantly decreased peak amplitude together with the proportion of the inactivating current component of Kv1.1-containing channels in primary hippocampal neurons, demonstrating that the ARTD10-PKCδ signaling cascade regulates native Kv1.1. Moreover, we show that the pharmacological blockade of ARTD10 increases excitability of hippocampal neurons.ConclusionsOur results, for the first time, suggest that MARylation by ARTD10 controls neuronal excitability.

Highlights

ADP-ribosylation is a ubiquitous post-translational modification that involves both mono- and polyADP-ribosylation
Mono-ADP-ribosylation by ARTD10 reduces protein kinase Cδ (PKCδ) activity To confirm PKCδ as a substrate of ARTD10, we performed in vitro ADP-ribosylation assays with the purified catalytic domain of ARTD10 fused to GST (GST-ARTD10 CAT) and of PKCδ fused to a 6-His-tag (His-PKCδ; Fig. 1a)
MARylation of PKCδ was less effective than auto-MARylation of ARTD10 (Fig. 1a), this result confirms PKCδ as a substrate of ARTD10 in vitro

Summary

Introduction

ADP-ribosylation is a ubiquitous post-translational modification that involves both mono- and polyADP-ribosylation. ARTD10, known as PARP10, mediates mono-ADP-ribosylation (MARylation) of substrate proteins. A previous screen identified protein kinase C delta (PKCδ) as a potential ARTD10 substrate, among several other kinases. ADP-ribosyltransferases (ARTs) regulate many cellular processes including DNA damage repair and transcriptional regulation by post-translational modification of their target proteins with ADP-ribose groups [1]. ARTD10 MARylates itself and core histones [4]. It shuttles between the nucleus and the cytosol, but resides mainly in the cytosol [6], suggesting that it has cytoplasmic substrates.

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