The DRD3 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population for loss-of-function studies of the dopamine D3 receptor. Derived from the HAP1 near-haploid human cell line, the product carries a targeted disruption of DRD3, abrogating expression of this Gi/o-coupled GPCR. The polyclonal pool contains diverse genetic modifications, enabling robust population-level assays without clonal selection. This model is suited for investigating D3 receptor signaling, drug responses, and disease mechanisms.
The HAP1 host line is a near-haploid human cell line derived from a male chronic myeloid leukemia patient and harbors the BCR-ABL oncogenic fusion. Its haploid genome simplifies gene knockout interpretation and facilitates haploid genetic screens. Widely validated for CRISPR/Cas9 editing, HAP1 cells enable efficient generation of polyclonal knockout populations. In this background, disruption of the single DRD3 allele abrogates receptor function, providing a clean loss-of-function system.
DRD3 encodes the dopamine D3 receptor, a Gi/o-coupled GPCR that, upon dopamine binding, inhibits adenylate cyclase to reduce cAMP and PKA activity. Downstream, this cascade regulates CREB, DARPP-32, and GIRK channels, while also activating ERK1/2 and AKT pathways. Receptor signaling is modulated by agonists (e.g., pramipexole) and desensitized via GRK2/GRK5 phosphorylation and ??-arrestin recruitment. The D3 receptor interacts with GNAI1, GNB1, GNG2, and crosstalks with DRD2 and ADORA2A. DRD3 knockout thus eliminates D3-mediated suppression of cAMP/PKA and modulation of MAPK cascades.
In the HAP1 context, DRD3 loss enables study of dopamine receptor function in a BCR-ABL-driven cancer cell line. Dopamine receptors can influence cancer cell proliferation and survival, making the interplay between D3 signaling and oncogenic kinases of high interest. These knockout cells allow dissection of D3 receptor contributions to MAPK and PI3K-Akt pathways in the presence of constitutive BCR-ABL activity. The near-haploid system also supports synthetic lethality and drug-sensitivity screens to identify D3-related vulnerabilities. Thus, the model serves as a versatile tool for exploring GPCR?Concogene crosstalk.
Applications include cAMP GloSensor assays, CREB phosphorylation ELISAs, and calcium flux analyses to characterize D3 signaling. The polyclonal knockout cells are suitable for high-throughput screening of D3 agonists/antagonists, aiding discovery of therapeutics for schizophrenia, Parkinson disease, and substance use disorders. They also serve as negative controls for antibody validation and can be incorporated into CRISPR screens to identify modulators of dopamine pathways. For further details, contact Ascent Research.
