The AP4M1 Knockout HT29 Polyclonal Cells product comprises a CRISPR/Cas9-edited polyclonal population derived from the HT29 human colorectal adenocarcinoma cell line, in which target-gene disruption of AP4M1 introduces a loss-of-function model for the mu-1 subunit of the adaptor protein complex 4 (AP-4). This polyclonal knockout pool avoids clonal selection and provides a heterogeneous genetic background, enabling robust assessment of AP-4-dependent phenotypes without single-cell cloning artifacts. The edited cells are suitable for biochemical, cell biological, and pharmacological investigations that require transient or stable perturbation of AP4M1 expression within an epithelial context.
The host cell line HT29 originates from a female colorectal adenocarcinoma and is widely employed as a model for colorectal cancer biology. These epithelial cells exhibit typical adherent growth, retain characteristic signaling pathways of colonic epithelium, and are commonly used to study tumor cell adhesion, migration, and autophagy-related processes. The HT29 background offers a relevant system for examining how AP-4-mediated trafficking integrates with oncogenic signaling and cellular stress responses, particularly given the emerging links between autophagy and colorectal cancer progression.
AP4M1 encodes the ?? subunit of the heterotetrameric AP-4 complex, which functions at the trans-Golgi network (TGN) to sort transmembrane cargo into vesicles destined for endosomes, lysosomes, and autophagosomes. The AP-4 complex, consisting of AP4M1 together with AP4E1, AP4B1, and AP4S1, interacts with clathrin and the ARF1 GTPase to recognize YXX??-type sorting signals present in cargo proteins such as amyloid precursor protein (APP), LAMP-2, and ATG9A. Nutrient availability signals and cargo recognition motifs act as upstream regulators of AP-4-dependent sorting, while downstream effects include the proper localization and processing of APP, lysosomal delivery of LAMP-2, and the autophagy-essential cycling of ATG9A. Disruption of AP4M1 therefore impairs the formation of functional AP-4 complexes, leading to defective trafficking and consequent autophagic flux inhibition and lysosomal dysfunction.
In the HT29 colorectal adenocarcinoma background, AP4M1 knockout creates a valuable model for dissecting the intersection between intracellular trafficking and cancer cell physiology. Loss of AP-4 function compromises the delivery of lysosomal and autophagosomal components, potentially sensitizing cells to metabolic stress and altering growth under nutrient-limiting conditions. This knockout system facilitates the study of AP-4-dependent mechanisms that contribute to hereditary spastic paraplegia type 50 (SPG50) and other neurodegenerative conditions, while also providing a platform to investigate how autophagy defects influence colorectal cancer cell survival, migration, and invasion. The epithelial origin of HT29 cells further permits analysis of polarized trafficking events that may be relevant to both neuronal and cancerous tissues.
Applications for the AP4M1 Knockout HT29 Polyclonal Cells span fundamental research into protein trafficking and autophagy, disease modeling of SPG50 and neurodegeneration, and drug discovery efforts aimed at lysosomal disorders. Typical assays include Western blotting to monitor APP processing and LC3B lipidation as indicators of autophagic flux, immunofluorescence microscopy for tracking the subcellular localization of AP-4 cargo proteins, and flow cytometry?Cbased quantitation of autophagic activity using fluorescent reporters. Co-immunoprecipitation experiments can assess AP-4 complex assembly, while migration and invasion assays explore the functional consequences of AP4M1 loss in a cancer context. For further information or technical support regarding this product, please contact Ascent Research.
