MARCHF5 Knockout Marc-145 Cell Line

The MARCHF5 Knockout Marc-145 Cell Line is a CRISPR/Cas9-edited knockout cell line derived from the Marc-145 host cell line, a kidney epithelial cell model isolated from Chlorocebus aethiops (African green monkey). This product provides a genetically defined loss-of-function model in which the mitochondrial E3 ubiquitin ligase MARCHF5 is disrupted through targeted gene editing. The knockout cell line retains the fundamental epithelial characteristics of the parental Marc-145 cells while nullifying MARCHF5 expression, enabling researchers to dissect its functions without the variability associated with transient knockdown approaches. The line is supplied as a stable, validated cell population suitable for a wide range of functional assays in virology, cell biology, and drug discovery.

Marc-145 cells are an established host system in virus research, particularly for the propagation and study of porcine reproductive and respiratory syndrome virus (PRRSV). Originally derived from African green monkey kidney tissue, this adherent epithelial cell line exhibits robust permissiveness to PRRSV infection and supports high-titer viral replication. Beyond PRRSV, Marc-145 cells have been employed in investigations of other viruses, making them a versatile platform for examining host?Cpathogen interactions. Their epithelial origin and mitochondrial activity also render them appropriate for exploring cellular processes such as mitochondrial dynamics, apoptosis, and innate immune signaling. The introduction of a MARCHF5 knockout in this background creates a unique tool to interrogate how mitochondrial quality control pathways intersect with viral infection cycles.

MARCHF5 encodes a mitochondrial outer membrane E3 ubiquitin ligase that serves as a central node in the regulation of mitochondrial fission, fusion, mitophagy, and apoptosis. Its activity is modulated by upstream factors including PINK1, Parkin, and protein kinase A in response to changes in mitochondrial membrane potential. MARCHF5 directly ubiquitylates key effectors such as Drp1 (a primary mediator of mitochondrial fission) and Mfn2 (a fusion-promoting GTPase), thereby controlling the balance between organelle fragmentation and elongation. The ligase also interacts with Bcl-2 family members Mcl-1, Bcl-2, and Bax, linking its ubiquitin-dependent functions to the intrinsic apoptotic pathway. Additionally, MARCHF5 targets MAVS, a critical adaptor in antiviral innate immunity, and has been implicated in the turnover of TDP-43, a protein associated with neurodegeneration. Through these interactions, MARCHF5 coordinates diverse signaling cascades that influence cell survival, mitochondrial homeostasis, and immune responses.

In the Marc-145 cell context, MARCHF5 knockout profoundly alters the regulatory network that governs mitochondrial behavior during viral challenge. The absence of MARCHF5-mediated ubiquitination disrupts the dynamic equilibrium of Drp1 and Mfn2, leading to aberrant mitochondrial morphology and impaired mitophagic clearance of damaged organelles. Concurrently, apoptotic signaling via Mcl-1, Bcl-2, and Bax is unconstrained, potentially sensitizing cells to death stimuli. Because PRRSV and other viruses manipulate mitochondrial functions to favor their replication, this knockout model allows researchers to directly assess how MARCHF5-dependent mitochondrial remodeling influences permissiveness to infection, viral propagation, and the induction of interferon-stimulated genes. The line thus represents a powerful system for identifying MARCHF5 substrates that are co-opted by viral proteins and for evaluating mitochondrial pathways as antiviral targets.

Typical applications of the MARCHF5 Knockout Marc-145 Cell Line encompass detailed kinetic studies of mitochondrial fission and fusion using immunofluorescence microscopy and JC-1 assays to monitor membrane potential. The model is well-suited for investigating PRRSV host factor requirements through viral titer assays and RT-qPCR analysis of interferon-stimulated genes, as well as for characterizing the ubiquitin-proteasome regulation of MARCHF5 targets such as Drp1, Mfn2, and TDP-43 by western blotting. Flow cytometry-based apoptosis assays enable dissection of cell death pathways altered by MARCHF5 loss. Moreover, the knockout cell line facilitates drug screening campaigns aimed at identifying small molecules that modulate mitochondrial dynamics or inhibit PRRSV replication, with potential antiviral therapeutic relevance. For further details, please contact Ascent Research.