Complex I binding by a virally encoded RNA regulates mitochondria-induced cell death

Area of Science:

• Virology
• Cell Biology
• Mitochondrial Biology

Background:

• Human cytomegalovirus (HCMV) infection disrupts cellular processes, potentially triggering apoptosis.
• HCMV encodes mechanisms to evade host cell death pathways during infection.

Purpose of the Study:

• To investigate how HCMV infection protects cells from apoptosis induced by mitochondrial complex I inhibition.
• To identify the viral component responsible for this protective effect.

Main Methods:

• Utilized rotenone, a mitochondrial complex I inhibitor, to induce apoptosis in HCMV-infected cells.
• Analyzed the role of a specific viral RNA (beta2.7) in mediating protection.
• Investigated the interaction between beta2.7 RNA, mitochondrial complex I, and apoptotic signaling pathways.

Main Results:

• HCMV infection conferred protection against rotenone-induced apoptosis.
• A 2.7-kilobase viral RNA (beta2.7) mediated this protection.
• Beta2.7 RNA interacted with mitochondrial complex I, preventing subunit gene relocalization and stabilizing mitochondrial membrane potential.
• This interaction maintained adenosine triphosphate (ATP) production, crucial for viral replication.

Conclusions:

• HCMV employs a viral RNA (beta2.7) to target mitochondrial complex I, a novel strategy to prevent apoptosis.
• This mechanism ensures host cell metabolic viability, supporting the HCMV life cycle.
• Targeting mitochondrial complex I by viral RNA represents a sophisticated method for modulating host cell metabolism during infection.