The DRD1 Knockout HAP1 Polyclonal Cells consist of a CRISPR/Cas9-edited polyclonal population with targeted disruption of the human DRD1 gene in the HAP1 cell line. This loss-of-function model eliminates dopamine D1 receptor expression, generating a heterogeneous knockout pool that captures a range of editing outcomes. The polyclonal format allows researchers to study D1 receptor-dependent signaling pathways without clonal artifacts, providing a robust tool for functional genomics, pharmacological screening, and signaling network analysis.
HAP1 cells are a near-haploid human chronic myeloid leukemia-derived line with adherent, fibroblast-like morphology and lacking the Philadelphia chromosome. Their haploid genome facilitates efficient CRISPR-based gene knockout, as disruption of a single allele is sufficient to ablate gene function. This genetic simplicity, combined with the cells?? stable growth characteristics, makes HAP1 an advantageous host for high-throughput genetic screens and for interrogating signaling pathways in a clean genetic background.
The DRD1 gene product, the dopamine D1 receptor, is a Gs-coupled GPCR that activates adenylyl cyclase (ADCY5) via GNAS, elevating cAMP. cAMP-dependent PKA phosphorylates DARPP-32 (PPP1R1B) at Thr34, converting it into a PP1 inhibitor, thereby regulating ERK1/2 and CREB. Receptor interactions with spinophilin (PPP1R9B) and calcyon (DRD1IP) further fine-tune signaling. Disruption of DRD1 abrogates dopamine-induced cAMP production and PKA activation, eliminating downstream phosphorylation events and altering transcriptional and electrophysiological responses.
In HAP1 cells, DRD1 knockout provides a defined system to study dopamine receptor signaling independent of neuronal complexity. The near-haploid background ensures clear genotype-phenotype correlations, enabling precise dissection of the cAMP/PKA/DARPP-32 pathway. Additionally, the leukemic origin of HAP1 cells allows exploration of dopamine receptor functions in cancer cell biology, including potential roles in proliferation, survival, and drug sensitivity, making this model relevant for both neurobiological and oncological research.
This knockout model supports cAMP GloSensor assays, phospho-DARPP-32 or phospho-ERK western blots, RT-qPCR for DRD1 mRNA, and viability assays after dopamine treatment. Applications include screening D1 modulators, validating antibodies, serving as a negative control for CRISPR experiments, and assessing polyclonal heterogeneity. For more information, contact Ascent Research.
