The GPAA1 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population targeting the GPAA1 gene in HAP1 cells. This loss-of-function model enables study of GPI anchor attachment and its impact on surface protein expression and signaling. The polyclonal format maintains edit heterogeneity, providing a robust population-level knockout without clonal selection, ideal for interrogating GPAA1-dependent processes in a near-haploid background.
HAP1 is a near-haploid human cell line derived from KBM-7 chronic myeloid leukemia, exhibiting adherent fibroblast-like morphology. Its near-haploid karyotype reduces functional redundancy and facilitates genetic manipulation, making it a preferred host for knockout studies. HAP1 cells maintain intact GPI biosynthetic pathways, providing a physiologically relevant platform to assess GPAA1 disruption.
GPAA1 encodes a subunit of the GPI transamidase complex, which also contains PIGK, PIGS, PIGT, and PIGU. This complex cleaves C-terminal signal peptides and covalently attaches GPI anchors to proteins, tethering them to the plasma membrane. GPAA1 is thus critical for surface expression of GPI-APs such as CD55, CD59, alkaline phosphatase, uPAR, and prion protein. Predicted transcription factors SP1 and YY1 regulate GPAA1, and its activity integrates into the GPI anchor biosynthesis pathway involving PIGA, PIGC, PIGH, and others. GPAA1 knockout abolishes transamidation, causing intracellular retention or secretion of unanchored proteins and global loss of surface GPI-APs.
In HAP1 cells, GPAA1 knockout models GPI anchor deficiency linked to diseases like paroxysmal nocturnal hemoglobinuria (PNH) and neurodevelopmental disorders. Loss of surface GPI-APs impairs complement resistance, adhesion, and signaling; absence of CD55 and CD59 renders cells susceptible to complement-mediated lysis. The myeloid leukemia background offers a context for studying hematopoietic malignancies and synthetic lethality. The polyclonal population??s heterogeneous edits suit pooled screening and functional genomics.
Applications include Western blotting for GPAA1, CD55, and CD59; flow cytometry to quantify surface GPI-AP loss; complement cytotoxicity assays; cell adhesion studies; RNA-seq; and drug sensitivity screens. This product supports research in GPI anchor biology, PNH disease modeling, neurodevelopmental disorders, and cancer therapeutic discovery. For more information, please contact Ascent Research.
