CALD1 Knockout HAP1 Polyclonal Cells provide a CRISPR/Cas9-edited polyclonal knockout cell population for loss-of-function studies of CALD1 in a human near-haploid background. The heterogeneous mixture carries diverse disruptive edits at the CALD1 locus, enabling robust functional studies without clonal isolation. The polyclonal format preserves genetic heterogeneity, advantageous for quantifying bulk migration, adhesion, and cytoskeletal reorganization phenotypes.
HAP1 is a fibroblast-like, adherent cell line derived from KBM-7 chronic myelogenous leukemia, featuring a predominantly haploid karyotype (except a diploid portion of chromosome 15). This near-haploid nature facilitates unambiguous genotype?Cphenotype correlation, as recessive mutations are not masked by a second allele. Its rapid proliferation and assay amenability make it a versatile gene-editing platform. The fibroblastoid morphology provides an appropriate context for investigating actin cytoskeleton dynamics and cell motility.
CALD1 encodes caldesmon, an actin- and tropomyosin-binding protein that negatively regulates actomyosin ATPase activity and stabilizes the actin cytoskeleton. Caldesmon phosphorylation by ERK1/2 or protein kinase C (PKC) relieves this inhibition, promoting actomyosin contractility. Caldesmon also interacts with calmodulin in a calcium-dependent manner, modulating its actin-binding affinity. Upstream, caldesmon expression is transcriptionally regulated by serum response factor (SRF) and its cofactor myocardin, linking it to Rho-associated kinase (ROCK) pathways. Caldesmon forms complexes with gelsolin, further influencing actin filament dynamics. Disruption of CALD1 is therefore expected to disinhibit actomyosin interactions, leading to increased cellular contractility, altered actin organization, and enhanced focal adhesion turnover, critical for cell migration and invasion.
In HAP1, the CALD1 knockout provides a tractable system to study caldesmon??s role in actin regulation without allelic confounding. The near-haploid state simplifies downstream genomic and transcriptomic analyses, such as RNA-seq and ATAC-seq, enabling clear interpretation of gene expression changes. Intrinsic mesenchymal migration makes these cells suitable for assessing the impact of caldesmon loss on 2D and 3D motility. The polyclonal format avoids clonal artifacts, yielding a range of knockout efficiencies useful for drug screening where variable target expression mirrors therapeutic contexts.
This product is suited for cancer migration and invasion studies, particularly in colorectal, gastric, and prostate cancer where CALD1 is implicated. Researchers can employ wound healing, transwell migration, and phalloidin-based actin staining to quantify phenotypic changes. Molecular characterization via immunoblotting for caldesmon/phospho-ERK, immunofluorescence for focal adhesion markers (paxillin, vinculin), and RT-qPCR for CALD1 isoforms can elucidate underlying mechanisms. Cell contractility assays and traction force microscopy directly measure actomyosin function. These applications make the CALD1 Knockout HAP1 Polyclonal Cells a valuable resource for exploring cytoskeletal regulation and therapeutic modulation of contractility. For further information, please contact Ascent Research.
