The AP5M1 Knockout HT29 Polyclonal Cells comprise a heterogeneous population of HT29 colorectal adenocarcinoma cells engineered via CRISPR/Cas9-mediated disruption of the AP5M1 gene, which encodes the mu1 subunit of the adaptor protein complex 5 (AP-5). As a polyclonal knockout cell pool, this product provides a loss-of-function model without clonal isolation, allowing researchers to study AP5M1-dependent processes in a bulk cell population context.
The HT29 host cell line originated from a primary colon adenocarcinoma of a 44-year-old Caucasian female and is widely used to study human intestinal epithelial biology. HT29 cells form polarized monolayers with functional tight junctions and can undergo partial enterocytic differentiation under appropriate conditions. This epithelial background makes HT29 cells particularly relevant for investigating colorectal cancer pathogenesis and the influence of cargo sorting pathways on cellular homeostasis.
AP5M1 encodes the mu1 subunit of the heterotetrameric AP-5 complex, which cooperates with the retromer complex and is recruited to late endosomal membranes by the active, GTP-bound form of Rab7. The AP-5 complex, together with clathrin and kinesin light chain KIF5A, orchestrates the retrieval of specific cargo proteins, including the cation-independent mannose-6-phosphate receptor (CI-MPR) and sortilin, from late endosomes to the trans-Golgi network (TGN). This process is essential for maintaining lysosomal enzyme trafficking and overall organelle integrity. The activity of AP5M1 and its binding partners, AP5B1, AP5S1, and AP5Z1, is further regulated by the lipid kinase PIKfyve. Disruption of AP5M1 impairs endosome-to-TGN transport, resulting in mislocalization of lysosomal hydrolases and accumulation of undegraded substrates within lysosomes.
In the HT29 colorectal adenocarcinoma model, AP5M1 knockout disrupts endosomal retrieval, potentially leading to aberrant signaling through growth factor receptors that rely on proper endosomal sorting. This dysregulation can manifest as altered cell proliferation, migration, and invasive capacity??key aspects of colorectal cancer progression. Furthermore, impaired lysosomal enzyme targeting may compromise cellular degradative capacity, sensitizing cancer cells to autophagy-dependent stressors. Given that AP5M1 mutations cause hereditary spastic paraplegia type SPG48, these polyclonal knockout cells also serve as a neurodegeneration model in an epithelial context, permitting cross-disciplinary studies of how endomembrane dysfunction drives different disease phenotypes.
This knockout cell pool is suited for a broad range of applications. Western blotting and immunofluorescence can verify AP5M1 loss and monitor CI-MPR redistribution, while co-immunoprecipitation with AP-5 antibodies dissects complex assembly. Flow cytometry quantifies cell surface CI-MPR or sortilin to assess trafficking defects, and lysosomal enzyme activity assays or autophagy flux measurements evaluate lysosomal function. In cancer biology, HT29 migration and invasion assays, combined with RT-qPCR of lysosomal hydrolase genes, reveal phenotypic consequences of AP5M1 disruption. These cells also support drug transporter regulation studies and endosomal trafficking screens. As a polyclonal population, they mirror heterogeneous editing outcomes in pooled screens, providing a robust tool for mechanistic and translational research. For additional details or to inquire about bulk orders, please contact Ascent Research.
