EXT1 Knockout Marc-145 Cell Line

This product is a CRISPR/Cas9-edited EXT1 knockout Marc-145 cell line, providing a defined loss-of-function model for the EXT1 gene in the Marc-145 epithelial host background. Using CRISPR/Cas9-mediated gene disruption, the cell line enables stable ablation of EXT1 function, facilitating investigation of heparan sulfate biosynthesis and growth factor signaling.

The Marc-145 cell line is a subclone of MA-104 African green monkey (Cercopithecus aethiops) kidney epithelial cells, selected for enhanced permissiveness to porcine reproductive and respiratory syndrome virus (PRRSV). This host cell line is extensively used in virus propagation, vaccine production, and host-pathogen interaction studies, providing a relevant platform for evaluating the role of host factors such as heparan sulfate in viral entry and replication.

EXT1 encodes a heparan sulfate polymerase that, in complex with EXT2, catalyzes the elongation of heparan sulfate chains on proteoglycans. EXT1 functions within the heparan sulfate biosynthetic pathway, upstream of modifying enzymes such as NDST1 and HS2ST1, and is regulated by transcription factors Sp1 and NF-Y, as well as TGF-??/BMP signaling. Knockout of EXT1 abolishes chain elongation, leading to the loss of mature heparan sulfate proteoglycans, including syndecans and glypicans. This disruption attenuates multiple signaling cascades, as heparan sulfate is a critical co-receptor for growth factors like FGF2 and Wnt3a. Consequently, downstream signaling through FGFR1 and other receptors is impaired, affecting pathways such as FGF, Wnt, Hedgehog, and BMP signaling, which drive processes including cell proliferation, differentiation, and adhesion.

In the Marc-145 background, EXT1 knockout provides a powerful tool to dissect the contribution of heparan sulfate to PRRSV infection. Since heparan sulfate often mediates initial viral attachment, ablation of EXT1 is expected to alter PRRSV binding and infectivity, offering insights into viral entry mechanisms and host determinants of susceptibility. Beyond virology, this model supports research into hereditary multiple exostoses, a condition caused by EXT1 mutations, as well as chondrosarcoma and osteoarthritis, where altered heparan sulfate signaling affects cartilage homeostasis. The epithelial origin of Marc-145 cells also permits studies on heparan sulfate??s role in kidney cell adhesion and migration, relevant to cancer metastasis.

Researchers can employ this knockout cell line in a wide range of applications, including PRRSV-host interaction studies using infectivity assays, heparan sulfate structural analysis via disaccharide profiling, and functional validation of HSPG loss by flow cytometry with the 10E4 antibody. Additional downstream assays, such as FGF2-induced phospho-ERK signaling and migration/invasion assays, allow characterization of growth factor responsiveness and metastatic potential. The model also supports drug testing targeting heparan sulfate-dependent pathways. For further details and ordering information, please contact Ascent Research.