Global phosphoproteomic analysis reveals ARMC10 as an AMPK substrate that regulates mitochondrial dynamics

Abstract

AMP-activated protein kinase (AMPK) is a key regulator of cellular energy homeostasis. Although AMPK has been studied extensively in cellular processes, understanding of its substrates and downstream functional network, and their contributions to cell fate and disease development, remains incomplete. To elucidate the AMPK-dependent signaling pathways, we performed global quantitative phosphoproteomic analysis using wild-type and AMPKα1/α2-double knockout cells and discovered 160 AMPK-dependent phosphorylation sites. Further analysis using an AMPK consensus phosphorylation motif indicated that 32 of these sites are likely direct AMPK phosphorylation sites. We validated one uncharacterized protein, ARMC10, and demonstrated that the S45 site of ARMC10 can be phosphorylated by AMPK both in vitro and in vivo. Moreover, ARMC10 overexpression was sufficient to promote mitochondrial fission, whereas ARMC10 knockout prevented AMPK-mediated mitochondrial fission. These results demonstrate that ARMC10 is an effector of AMPK that participates in dynamic regulation of mitochondrial fission and fusion.

Quantitative Phosphoproteomics Reveals Cell Alignment and Mitochondrial Length Change under Cyclic Stretching in Lung Cells

“…The characterization of the protein phosphorylation status underlying stimulus-induced signaling changes may provide important insights into the regulation of physiological events in cells. Recent advances in quantitative phosphoproteomic profiling allow researchers to study the aberrant regulation of signaling pathways [7][8][9][10].…”

An Atlas of Phosphorylation and Proteolytic Processing Events During Excitotoxic Neuronal Death Reveals New Therapeutic Opportunities

“…The sequences around phosphosites identified in these proteins show strong conformity to the optimal phosphorylation motif of AMPK ( Figure 4C) (Schaffer et al, 2015). Furthermore, AMPK phosphorylation of these proteins at the identified phosphosites in cultured cells and/or in vivo has been documented (Chen et al, 2008;Chen et al, 2019;Ding et al, 2017;Fraser et al, 2014;Shen et al, 2013).…”

“…In our endeavour to discover these potential therapeutic targets, we used a multi-dimensional quantitative proteomic approach to identify the pathological cellular events in cultured primary neurons undergoing excitotoxic cell death. Excitotoxicity is initiated by over-stimulation of ionotropic glutamate receptors (iGluRs), especially the N-methyl-D-aspartate (NMDA) receptors (Choi, 1988;Olney, 1969;Simon et al, 1984), which permit excessive influx of extracellular calcium (Ca 2+ ) into the cytosol to over-activate proteases (Ginet et al, 2014;Lankiewicz et al, 2000;Wang et al, 1996;Yamashima et al, 1998), neuronal nitric oxide synthase (nNOS) (Sattler et al, 1999) and NADPH oxidase 2 (NOX2) (Brennan et al, 2009). The excitotoxicity-activated proteases cleave specific neuronal proteins to modulate their activities, biological functions and stability (Tominaga et al, 1998;Wang et al, 1996).…”

Armadillo repeat-containing protein 1 is a dual localization protein associated with mitochondrial intermembrane space bridging complex

“…A recent report identifies a family of Arm repeat-containing proteins encoded by genes located on the X chromosome, the so-called ArmCx cluster, which have evolved from a common ancestral gene ArmC10 and localize to mitochondria [31]. The ancestral ArmC10 protein has been shown to be a substrate of AMP-activated protein kinase (AMPK) and to be involved in mitochondrial fission [32].…”