51. PYCR1 and PYCR2 Interact and Collaborate with RRM2B to Protect Cells from Overt Oxidative Stress
- Author
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Mabel Bin Er Lee, Chun A. Changou, Leila Su, Michelle Tang, Mingming Su, Yun Yen, Shuya Hu, Wei Jia, Willem den Besten, Mei-Ling Kuo, Sonja Hess, Chih Ming Chou, and Michael J. Sweredoski
- Subjects
0301 basic medicine ,Recombinant Fusion Proteins ,Cell Cycle Proteins ,Biology ,Reductase ,Mitochondrion ,medicine.disease_cause ,Article ,Antioxidants ,Mass Spectrometry ,Cell Line ,03 medical and health sciences ,Protein Interaction Mapping ,Ribonucleotide Reductases ,medicine ,Animals ,Humans ,Gene silencing ,Gene Silencing ,Fragmentation (cell biology) ,Telomerase ,Zebrafish ,Multidisciplinary ,Cell Cycle Checkpoints ,Mitochondria ,Isoenzymes ,Oxidative Stress ,Protein Transport ,030104 developmental biology ,Ribonucleotide reductase ,Biochemistry ,Cell culture ,Gene Knockdown Techniques ,Multiprotein Complexes ,Pyrroline Carboxylate Reductases ,Tumor Suppressor Protein p53 ,Signal transduction ,Oxidative stress ,Protein Binding ,Signal Transduction - Abstract
Ribonucleotide reductase small subunit B (RRM2B) is a stress response protein that protects normal human fibroblasts from oxidative stress. However, the underlying mechanism that governs this function is not entirely understood. To identify factors that interact with RRM2B and mediate anti-oxidation function, large-scale purification of human Flag-tagged RRM2B complexes was performed. Pyrroline-5-carboxylate reductase 1 and 2 (PYCR1, PYCR2) were identified by mass spectrometry analysis as components of RRM2B complexes. Silencing of both PYCR1 and PYCR2 by expressing short hairpin RNAs induced defects in cell proliferation, partial fragmentation of the mitochondrial network and hypersensitivity to oxidative stress in hTERT-immortalized human foreskin fibroblasts (HFF-hTERT). Moderate overexpression of RRM2B, comparable to stress-induced level, protected cells from oxidative stress. Silencing of both PYCR1 and PYCR2 completely abolished anti-oxidation activity of RRM2B, demonstrating a functional collaboration of these metabolic enzymes in response to oxidative stress.
- Published
- 2016