The C2CD2 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed for the targeted disruption of the C2CD2 gene in the HAP1 human cell line. This polyclonal pool provides a genetically heterogeneous loss-of-function model that avoids clonal artifacts while enabling robust analysis of C2CD2-dependent cellular processes. By eliminating functional C2CD2 expression, the cells facilitate investigation of calcium-regulated insulin exocytosis and the broader SNARE-mediated secretory machinery in a tractable near-haploid genetic background. The product is delivered as a viable polyclonal population, suitable for immediate expansion and downstream functional assays, and has been validated for target-gene disruption at the protein level.
HAP1 is a near-haploid human cell line derived from the KBM-7 chronic myelogenous leukemia (CML) model. It retains the BCR-ABL1 fusion oncogene characteristic of CML and is p53-deficient, endowing it with a stable karyotype and high sensitivity to genetic perturbation. The haploid state reduces functional redundancy, making HAP1 a widely adopted platform for CRISPR knockout screens and mechanistic dissection of gene function. Although not a pancreatic beta cell line, HAP1 expresses core components of the regulated exocytic pathway, including SNARE proteins and calcium-sensing machinery, rendering it suitable for interrogating vesicle fusion dynamics. Its rapid growth and genetic simplicity allow for efficient knockout generation and reproducible phenotypic readouts, particularly in studies linking genotype to secretory function.
C2CD2 encodes a C2 domain-containing protein that binds calcium and phospholipids, acting as a key mediator of insulin secretory granule exocytosis. The protein functions downstream of extracellular glucose sensing and subsequent calcium influx triggered by KATP channel closure. Upon intracellular calcium elevation, C2CD2 interacts with synaptotagmin-7, SNAP25, syntaxin-4, and VAMP2 to promote SNARE complex assembly and granule-plasma membrane fusion. This molecular cascade couples metabolic signals to insulin release, and loss of C2CD2 disrupts the calcium-dependent docking and fusion steps, impairing regulated exocytosis. The mechanistic pathway involves voltage-gated calcium channels, synaptotagmin-7 as a calcium sensor, and the core SNARE proteins SNAP25, syntaxin-4, and VAMP2 that directly execute membrane merger.
Disrupting C2CD2 in the HAP1 background creates a simplified human cell model for studying defective insulin exocytosis and the broader role of calcium-dependent membrane fusion processes. Although HAP1 lacks insulin gene expression, it retains the fundamental exocytic machinery, allowing dissection of C2CD2??s function in SNARE-mediated trafficking without the complexity of beta-cell-specific signaling networks. The p53 deficiency and haploid genetics further streamline knockout validation and minimize compensatory responses, yielding a clean loss-of-function context for analyzing protein interactions and secretory dynamics. This model is particularly valuable for probing how C2CD2 coordinates with synaptotagmin-7 and SNARE partners to regulate vesicle priming and fusion, and for testing the effects of genetic or pharmacological modulators on these interactions.
Researchers can employ the C2CD2 Knockout HAP1 Polyclonal Cells in a variety of experimental paradigms, including glucose-stimulated insulin secretion (GSIS) reconstitution assays, calcium imaging to monitor stimulus-coupled flux, and co-immunoprecipitation studies to map C2CD2-containing protein complexes. Membrane capacitance measurements and western blot analysis of SNARE protein recruitment provide quantitative readouts of exocytosis efficiency. Applications extend to drug discovery screens for enhancers of insulin secretion and mechanistic studies of metabolic disorders such as type 2 diabetes and glucose intolerance. The cells are also suitable for genetic rescue experiments to validate C2CD2 functional domains. For further information, please contact Ascent Research.
