ARFGAP3 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the HAP1 human near-haploid cell line, providing a loss-of-function model for studying COPI-dependent retrograde trafficking. The product consists of a heterogeneous pool of cells with targeted disruption of the ARFGAP3 gene, generated using a CRISPR/Cas9-mediated gene-editing approach that introduces genetic heterogeneity without clonal isolation. This population-based format preserves the advantages of the HAP1 background while avoiding the limitations associated with single-cell-derived clones, making it suitable for applications where phenotypic consistency is assessed across a polyclonal population.
The HAP1 cell line is an adherent, fibroblast-like human cell line originally derived from the KBM-7 chronic myeloid leukemia cell line. Its near-haploid karyotype, with a single copy of most chromosomes, significantly facilitates loss-of-function genetic screens by enabling straightforward genotype-phenotype correlations. HAP1 cells exhibit robust growth properties and are amenable to a wide range of standard molecular and cell biology techniques, including transfection, immunofluorescence, and biochemical assays. This unique genetic background makes HAP1 an ideal host for generating gene-knockout populations for the study of gene function in fundamental cellular processes.
ARFGAP3 encodes a GTPase-activating protein (GAP) for ADP-ribosylation factor 1 (ARF1), a small GTPase that plays a central role in COPI vesicle formation and uncoating. Upon recruitment to Golgi membranes through interactions with ARF1-GTP and the COPI coatomer complex, ARFGAP3 accelerates GTP hydrolysis on ARF1, leading to the production of ARF1-GDP. This activity triggers COPI coat disassembly, a critical step for recycling KDEL receptors and other cargo from the Golgi back to the endoplasmic reticulum (ER). ARFGAP3 directly interacts with ARF1, COPI subunits such as ??-COP and ??-COP, the cargo receptor p23, and the KDEL receptor. It functions downstream of ARF1 activation and upstream of COPI coat dissociation, thereby influencing Golgi morphology and retrograde transport. Representative pathway components include ARF1, the COPI coatomer, the KDEL receptor, ERGIC-53, and Golgi SNAREs.
In the HAP1 cell context, ARFGAP3 knockout disrupts the normal cycle of COPI vesicle uncoating, leading to the accumulation of coated vesicles and an imbalance in Golgi-to-ER retrograde trafficking. This disruption provides a functional model to investigate the cellular consequences of defective retrograde transport, including Golgi stress responses and alterations in organelle morphology. Because ARFGAP3 has been implicated in cancer and Golgi-related trafficking disorders, this knockout population offers a versatile platform for exploring disease mechanisms. The near-haploid genome of HAP1 further enhances the model??s utility for genetic screens aimed at identifying modulators of COPI-dependent pathways or potential therapeutic targets.
This product is designed for a broad range of research applications, including the study of COPI-dependent Golgi-to-ER trafficking, Golgi stress pathways, and drug target validation for Golgi-associated diseases. Representative assays include Western blotting to monitor ARFGAP3 and COPI protein levels, immunofluorescence microscopy using Golgi markers (GM130, Giantin) and ER markers (KDEL), and functional retrograde transport assays. Electron microscopy can be employed to visualize ultrastructural changes in the Golgi apparatus. Additionally, cell viability assays and the haploid genetic screening capabilities of HAP1 enable systematic exploration of gene function. For further information, please contact Ascent Research.
