The HDDC3 Knockout HAP1 Polyclonal Cells are a genetically engineered cell population in which CRISPR/Cas9 technology has been used to disrupt the HDDC3 locus, generating a heterogeneous pool of loss-of-function alleles. This polyclonal knockout population avoids clonal biases and provides a robust model for interrogating the functional consequences of eliminating the ppGpp hydrolase MESH1. The product is delivered as live cells optimized for immediate use in downstream assays, ensuring high viability and consistent performance across experimental replicates.
The HAP1 cell line is a near-haploid human myeloid leukemia model derived from a chronic myeloid leukemia patient. Its near-haploid karyotype, with a single copy of most genes, facilitates unambiguous functional genomics studies and has made HAP1 a workhorse for haploid genetic screens. This leukemic background further offers a physiologically relevant context for exploring oncogenic signaling, stress adaptation, and the mechanisms that drive uncontrolled proliferation, making it an ideal host for studying HDDC3??s role in cancer biology.
HDDC3 encodes the enzyme MESH1, a cytosolic ppGpp hydrolase that serves as a critical negative regulator of the stringent response. By cleaving the alarmone guanosine pentaphosphate (ppGpp), MESH1 dampens stress-induced signaling cascades that are activated by nutrient deprivation and cellular stress. The ppGpp/MESH1 axis operates downstream of these upstream stressors to modulate key downstream processes, including autophagy, ribosome biogenesis, and mRNA translation. Furthermore, MESH1-mediated ppGpp hydrolysis influences mTOR pathway activity, linking nucleotide metabolism directly to cellular growth and proliferation control.
Disruption of HDDC3 in the HAP1 background removes the primary enzymatic brake on ppGpp accumulation, leading to enhanced stress signaling and potential dysregulation of autophagy and protein synthesis. The polyclonal nature of this knockout product ensures broad representation of mutations while maintaining effective gene disruption, making it well-suited for population-level studies of the stringent response. Researchers can leverage this model to explore how aberrant ppGpp metabolism contributes to the survival and proliferative capacity of leukemic cells and to identify vulnerabilities in cancer cells that rely on MESH1 for stress adaptation.
These knockout cells support a wide range of research applications, including fundamental investigations into nucleotide-mediated stress signaling, autophagy regulation, and cancer biology. They are particularly valuable for drug screening initiatives targeting the ppGpp?CMESH1?CmTOR pathway, as well as for transcriptomic and proteomic profiling under nutrient-depleted conditions. Standard assays such as western blotting, ppGpp quantification, autophagy flux measurements, proliferation assays, and RNA-seq are readily applicable. For technical support or ordering information, please contact Ascent Research.
