Knockout of the Ribonuclease Inhibitor Gene Leaves Human Cells Vulnerable to Secretory Ribonucleases

Biochemistry. 2016 Nov 22;55(46):6359-6362. doi: 10.1021/acs.biochem.6b01003. Epub 2016 Nov 8.

Abstract

Ribonuclease inhibitor (RNH1) is a cytosolic protein that binds with femtomolar affinity to human ribonuclease 1 (RNase 1) and homologous secretory ribonucleases. RNH1 contains 32 cysteine residues and has been implicated as an antioxidant. Here, we use CRISPR-Cas9 to knock out RNH1 in HeLa cells. We find that cellular RNH1 affords marked protection from the lethal ribonucleolytic activity of RNase 1 but not from oxidants. We conclude that RNH1 protects cytosolic RNA from invading ribonucleases.

MeSH terms

  • CRISPR-Cas Systems
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Proliferation / drug effects
  • Cell Proliferation / genetics
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Dose-Response Relationship, Drug
  • HeLa Cells
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Oxidants / pharmacology
  • RNA, Neoplasm / metabolism*
  • Ribonuclease, Pancreatic / metabolism*

Substances

  • Carrier Proteins
  • Oxidants
  • RNA, Neoplasm
  • RNH1 protein, human
  • Hydrogen Peroxide
  • Ribonuclease, Pancreatic