The ARHGEF18 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the HAP1 cell line, designed as a loss-of-function model for the RhoA guanine nucleotide exchange factor ARHGEF18 (p114RhoGEF). This product results from CRISPR/Cas9-mediated gene disruption at the ARHGEF18 locus, generating a heterogeneous pool of cells with abrogated ARHGEF18 expression. The polyclonal format bypasses clonal isolation, maintaining population diversity while enabling robust functional assays of RhoA signaling.
The parental HAP1 cell line is a near-haploid human line of chronic myeloid leukemia origin, exhibiting fibroblast-like morphology and a single copy of most genes. This near-haploid karyotype is ideal for genetic screens, as it ensures complete functional knockout and reduces redundancy. HAP1 cells retain intact integrin and Rho GTPase signaling pathways, making them a relevant model for studying cytoskeletal regulation and cell adhesion.
ARHGEF18 encodes a GEF that activates RhoA by promoting GDP-to-GTP exchange. Upstream signals from integrins or G protein-coupled receptors, acting through G??12/13, stimulate ARHGEF18, leading to RhoA-GTP accumulation. Downstream, RhoA-GTP activates ROCK1/2, which phosphorylate LIMK and MLC. LIMK inhibits cofilin to stabilize actin filaments, while MLC phosphorylation enhances actomyosin contractility, driving stress fiber formation and focal adhesion maturation. ARHGEF18 thus centrally regulates cytoskeletal dynamics, cell adhesion, and migration.
Disrupting ARHGEF18 in the near-haploid HAP1 background yields a pronounced loss of RhoA activation, manifested by reduced stress fibers, impaired focal adhesions, and diminished contractility. The single-copy target ensures high penetrance of the knockout phenotype, minimizing compensation from related GEFs like PDZ-RhoGEF or LARG. This model enables precise dissection of p114RhoGEF-specific functions in cell morphology and motility, distinct from other G??12/13-coupled RhoGEFs.
These polyclonal knockout cells are suited for RhoA-GTP pull-down assays, western blot analysis of phospho-MLC and phospho-cofilin, and immunofluorescence for actin stress fibers. Functional assays such as transwell migration and wound healing quantify cell motility defects, while focal adhesion staining reveals adhesion complex remodeling. Applications extend to cancer metastasis research, haploid genetic screening for RhoA pathway modulators, and validation of therapeutic targets. For inquiries, please contact Ascent Research.
