Meiotic viral attenuation through an ancestral apoptotic pathway.

Proceedings of the National Academy of Sciences of the United States of America (2019-07-04)
Jie Gao, Sabrina Chau, Fuad Chowdhury, Tina Zhou, Saif Hossain, G Angus McQuibban, Marc D Meneghini
ABSTRACT

The programmed release of apoptogenic proteins from mitochondria is a core event of apoptosis, although ancestral roles of this phenomenon are not known. In mammals, one such apoptogenic protein is Endonuclease G (EndoG), a conserved mitochondrial nuclease that fragments the DNA of dying cells. In this work, we show that budding yeast executes meiotically programmed mitochondrial release of an EndoG homolog, Nuc1, during sporulation. In contrast to EndoG's ostensible pro-death function during apoptosis, Nuc1 mitochondrial release is pro-survival, attenuating the cytosolic L-A and Killer double-stranded RNA mycoviruses and protecting meiotic progeny from the catastrophic consequences of their derepression. The protective viral attenuation role of this pathway illuminates a primordial role for mitochondrial release of EndoG, and perhaps of apoptosis itself.

MATERIALS
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Product Description

Sigma-Aldrich
Monoclonal ANTI-FLAG® M2 antibody produced in mouse, 1 mg/mL, clone M2, affinity isolated antibody, buffered aqueous solution (50% glycerol, 10 mM sodium phosphate, and 150 mM NaCl, pH 7.4)
Sigma-Aldrich
Phenol solution, Saturated with 0.1 M citrate buffer, pH 4.3 ± 0.2, BioReagent, for molecular biology