The INPP5K Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population in the near-haploid HAP1 human cell line with targeted disruption of the INPP5K gene. This loss-of-function model eliminates expression of SKIP, a dual-specificity inositol phosphatase, providing a versatile tool for studying the intersection of metabolic signaling, endoplasmic reticulum stress, and cytoskeletal dynamics. The polyclonal format encompasses a heterogeneous pool of edited cells, making it suitable for pooled functional genomics screens, drug target validation, and bulk biochemical assays.
HAP1 is a near-haploid human cell line derived from the male chronic myeloid leukemia (CML) cell line KBM-7. It is adherent and retains a largely haploid karyotype, except for a disomic fragment of chromosome 15, enabling efficient gene disruption and clear genotype-phenotype correlation. Widely employed in cancer biology and haploid genetic screening, HAP1 serves as a robust platform for generating CRISPR/Cas9-mediated knockout models without the complexity of diploid compensation mechanisms.
INPP5K encodes SKIP, which functions as a negative regulator of the PI3K/Akt signaling pathway by hydrolyzing the second messenger PIP3 to PIP2, and also modulates endoplasmic reticulum stress responses through dephosphorylation of IP4. Transcriptionally, INPP5K is upregulated by spliced XBP1, a key downstream effector of the IRE1?? arm of the unfolded protein response. At the ER membrane, SKIP interacts with GRP78/BiP, IRE1??, and the E3 ligase HRD1, influencing both the unfolded protein response and ER-associated degradation. Additionally, SKIP binds cofilin and integrin-linked kinase to regulate actin cytoskeleton organization, thereby impacting cell morphology and migration. Representative pathway components include PI3K, PDK1, Akt, mTOR, PTEN, and PIP3; downstream, loss of INPP5K leads to elevated phospho-Akt levels, hyperactivation of ER stress sensors PERK and IRE1??, and altered cofilin phosphorylation.
In HAP1 cells, disruption of INPP5K likely enhances basal Akt signaling and insulin sensitivity while sensitizing the ER stress network, making this model particularly relevant for research into congenital muscular dystrophy with cataracts and intellectual disability, insulin resistance, and type 2 diabetes. The haploid background allows unambiguous assessment of phenotypic changes arising from SKIP deficiency, and the polyclonal nature permits evaluation of diverse allelic effects on cell signaling and stress responses.
These polyclonal knockout cells are well-suited for a broad range of experimental applications. Researchers can perform western blotting for phospho-Akt to monitor PI3K pathway activity, RT-qPCR for XBP1 splicing to assess IRE1?? activation, and co-immunoprecipitation to examine SKIP?CGRP78 interactions. Insulin signaling can be profiled via phospho-kinase arrays, while ER stress induction with tunicamycin reveals UPR dynamics. Immunofluorescence for actin detects cytoskeletal reorganization, and flow cytometry enables quantification of apoptosis or proliferation. This model thus supports studies in cancer cell signaling, metabolic disease, and muscular dystrophy. For more information, please contact Ascent Research.
