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BioMed Research International
Volume 2019, Article ID 5320747, 8 pages
https://doi.org/10.1155/2019/5320747
Research Article

Role of PKR in the Inhibition of Proliferation and Translation by Polycystin-1

1Department of Oncology, The Second Hospital, Jilin University, Changchun 130041, China
2Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, T6G2H7, Canada
3National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan 430086, China

Correspondence should be addressed to Jianzheng Yang; moc.361@5002gnehzjgnay and Zuocheng Wang; moc.361@gnawgnehcouz

Received 15 February 2019; Revised 19 May 2019; Accepted 2 June 2019; Published 23 June 2019

Academic Editor: Paul M. Tulkens

Copyright © 2019 Yan Tang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Autosomal dominant polycystic kidney disease (ADPKD) is mainly caused by mutations in the PKD1 (~85%) or PKD2 (~15%) gene which, respectively, encode polycystin-1 (PC1) and polycystin-2 (PC2). How PC1 regulates cell proliferation and apoptosis has been studied for decades but the underlying mechanisms remain controversial. Protein kinase RNA-activated (PKR) is activated by interferons or double-stranded RNAs, inhibits protein translation, and induces cell apoptosis. In a previous study, we found that PC1 reduces apoptosis through suppressing the PKR/eIF2α signaling. Whether and how PKR is involved in PC1-inhibited proliferation and protein synthesis remains unknown. Here we found that knockdown of PKR abolishes PC1-inhibited proliferation and translation. Because suppressed PKR-eIF2α signaling/activity by PC1 would stimulate, rather than inhibit, the proliferation and translation, we examined the effect of dominant negative PKR mutant K296R that has no kinase activity and found that it enhances the inhibition of proliferation and translation by PC1. Thus, our study showed that inhibition of cell proliferation and protein synthesis by PC1 is mediated by the total expression but not the kinase activity of PKR, possibly through physical association.