Dataset Information

HCV Hypo- vs. Hyper-Phosphorylated NS5A Interactome

ABSTRACT: Chronic hepatitis C virus (HCV) infection is a leading cause of liver cancer. HCV propagation and oncogenicity depend in part on the phosphorylation states of its non-structural protein 5A (NS5A); however, little is known about how hypo- or hyper-phosphorylated NS5A functions. Here, we segregated hypo- from hyper-phosphorylated NS5A in HCV-infected Huh7.5.1 cells with two custom-made specific antibodies and differentiated their interacting proteins with dimethyl labeling-based quantitative proteomics. Bioinformatics analysis revealed that hyper-phosphorylated NS5A preferentially binds the polymerase II-associated factor 1 complex known to alter host gene expression involved in cancer progression. In contrast, hypo-phosphorylated NS5A binds proteins involved in host antiviral response. Moreover, we found that the hypo-phosphorylated NS5A binds DNA-dependent protein kinase catalytic subunit (DNA-PKcs) predicted to phosphorylate NS5A at serine 232, a key amino acid that governs NS5A transition from hypo- to hyper-phosphorylation state. Inhibition of DNA-PKcs with an inhibitor or via gene-specific knockdown significantly reduced serine 232 phosphorylation and NS5A hyper-phosphorylation. Collectively, we have identified a protein kinase that regulates a delicate balance of NS5A between hypo- and hyper-phosphorylation states respectively involved in host antiviral responses and liver cancer progression.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Hepatocyte, Cell Culture

DISEASE(S): Hepatocellular Carcinoma

SUBMITTER: Ming-Jiun Yu

LAB HEAD: Ming-Jiun Yu

PROVIDER: PXD012767 | Pride | 2019-06-17

REPOSITORIES: pride

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Differential Proteomics Reveals Discrete Functions of Proteins Interacting with Hypo- versus Hyper-phosphorylated NS5A of the Hepatitis C Virus.

Pan Ting-Chun TC Lo Chieh-Wen CW Chong Weng Man WM Tsai Chia-Ni CN Lee Kuan-Ying KY Chen Pin-Yin PY Liao Jung-Chi JC Yu Ming-Jiun MJ

Journal of proteome research 20190621 7

Protein phosphorylation is a reversible post-translational modification that regulates many biological processes in almost all living forms. In the case of the hepatitis C virus (HCV), the nonstructural protein 5A (NS5A) is believed to transit between hypo- and hyper-phosphorylated forms that interact with host proteins to execute different functions; however, little was known about the proteins that bind either form of NS5A. Here, we generated two high-quality antibodies specific to serine 235 ...[more]

PMID: 31199160

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