The KPRP Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the keratinocyte proline-rich protein (KPRP) gene in the human near-haploid HAP1 cell line. This polyclonal population provides a powerful loss-of-function model for investigating KPRP-dependent mechanisms without the need for single-cell cloning, preserving genetic heterogeneity that can reflect more physiologically relevant cellular responses. Through CRISPR/Cas9-mediated gene disruption, the cells enable systematic analysis of KPRP??s roles in keratinocyte differentiation and epidermal barrier integrity.
The HAP1 host cell line is derived from the KBM-7 chronic myeloid leukemia (CML) line and exhibits a near-haploid karyotype with adherent, fibroblast-like morphology. Its near-haploid genome makes HAP1 an exceptionally tractable system for genetic screens and gene-editing studies, as the presence of a single allele per gene facilitates the generation of complete loss-of-function phenotypes. While HAP1 originates from a hematopoietic malignancy, its utility extends to diverse biological questions, including cell signaling and differentiation pathways.
KPRP encodes a proline-rich protein that serves as a critical precursor for the cornified envelope, a structure essential for the mechanical integrity and barrier function of the epidermis. During terminal differentiation of keratinocytes, KPRP is transcriptionally regulated by transcription factors such as p63 and AP-1, downstream of calcium-induced and Notch signaling pathways. Once expressed, KPRP becomes cross-linked by transglutaminases into the cornified envelope, where it interacts with structural proteins including loricrin, involucrin, and filaggrin, as well as small proline-rich proteins. This assembly reinforces the epidermal barrier, and its disruption is linked to skin disorders like psoriasis and atopic dermatitis.
In the HAP1 background, the KPRP knockout model offers a unique platform to dissect the genetic networks controlling cornified envelope formation. Although HAP1 cells do not naturally undergo keratinocyte differentiation, they can be used to study KPRP??s biochemical properties, protein-protein interactions, and regulatory pathways when combined with exogenous expression of differentiation factors. Moreover, the near-haploid state simplifies the mapping of genetic interactions and synthetic lethality screens, enabling the identification of novel modulators of KPRP-associated functions and potential therapeutic targets for barrier-related diseases.
These polyclonal knockout cells are suited for a range of experimental applications, including immunofluorescence detection of cornified envelope proteins after induced differentiation, Western blotting for KPRP and its interaction partners, RT-qPCR analysis of epidermal gene expression programs, and transepithelial resistance assays when cultured in barrier-forming models. They can also be employed in CRISPR-based genetic modifier screens to uncover novel regulators of keratinization. For further details or assistance with experimental design, please contact Ascent Research.
