The CCNI Knockout HAP1 Polyclonal Cells product provides a CRISPR/Cas9-edited polyclonal cell population with targeted disruption of the CCNI gene in the human HAP1 cell line. This knockout model enables loss-of-function studies of cyclin I, an atypical cyclin that forms active kinase complexes with CDK5. The polyclonal format offers a heterogeneous pool of edited cells, facilitating population-level functional genomics analyses without the biases associated with single-cell clones.
The HAP1 host cell line is a near-haploid, fibroblast-like cell derived from a male chronic myeloid leukemia patient. As an adherent, KBM-7 derivative, HAP1 retains a stable near-haploid karyotype that eliminates issues of allelic complexity, making it exceptionally suited for knockout and functional genomic screens. Its robust growth characteristics and compatibility with standard cell culture techniques further enhance its utility for high-throughput applications.
CCNI encodes cyclin I, which interacts with CDK5 and its regulatory partners p35 and p39 to form an active kinase complex. This complex is regulated by upstream signals including B-Myb, STAT3, EGF/MAPK signaling, and pro-inflammatory cytokines. Downstream, cyclin I-CDK5 promotes cell survival by phosphorylating and stabilizing anti-apoptotic proteins such as Bcl-2, thereby inhibiting caspase-3 cleavage and apoptosis. Additionally, cyclin I enhances STAT3 transcriptional activity, which can activate NF-??B, integrating survival and inflammatory signals. Thus, cyclin I functions at a nexus of the Cyclin-CDK, JAK-STAT, and apoptosis signaling pathways.
In the context of HAP1 cells, knockout of CCNI disrupts the cyclin I-CDK5 survival axis, providing a well-defined system to interrogate the molecular dependencies of apoptotic regulation. The near-haploid genome simplifies the interpretation of knockout phenotypes, reducing compensatory effects from gene redundancy. This model is particularly valuable for dissecting the role of cyclin I in chemoresistant cancers, such as acute myeloid leukemia, and in neuronal survival pathways relevant to Alzheimer’s disease, where CDK5 dysregulation is implicated.
Researchers can employ CCNI Knockout HAP1 Polyclonal Cells in a wide range of applications, including functional genomics, apoptosis mechanistic studies, and drug resistance screening. Representative assay techniques compatible with this model include Western blotting for CCNI and CDK5, CDK5 kinase activity assays, caspase-3 cleavage detection, MTT cell viability measurements, immunofluorescence for cyclin I localization, RT-qPCR for CCNI mRNA, co-immunoprecipitation of the cyclin I-CDK5 complex, and flow-cytometric Annexin V apoptosis assays. The polyclonal population is also suitable for phospho-Bcl-2 ELISA and other phosphoprotein analyses. For further information or technical support, please contact Ascent Research.
