GRAMD1C Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human A-549 lung adenocarcinoma cell line, in which the GRAMD1C gene has been disrupted to generate a loss-of-function model. This product provides a heterogeneous pool of gene-edited cells suitable for studying cholesterol transport, endoplasmic reticulum?Cplasma membrane (ER-PM) contact site dynamics, and associated signaling pathways. The polyclonal format captures the cellular variability relevant to tumor biology and lipid metabolism research, offering a robust system for functional studies without clonal selection bias.
The A-549 host cell line is a widely used carcinoma-derived adherent cell line with epithelial morphology, originally isolated from a human lung adenocarcinoma. It serves as an established model for alveolar Type II-like epithelial cells, exhibiting characteristics relevant to pulmonary surfactant production and metabolic activity. This cellular context is informative for investigating lipid homeostasis and membrane biology, as A-549 cells maintain active cholesterol metabolism and ER-PM contact site architecture.
GRAMD1C encodes a cholesterol transport protein that localizes to ER-PM contact sites via its GRAM domain, which senses cholesterol and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). It facilitates non-vesicular cholesterol transfer to the plasma membrane, thereby influencing membrane lipid composition and integrity. GRAMD1C interacts with VAPA/VAPB, OSBP, and extended synaptotagmin (E-Syt) proteins, and its activity is regulated upstream by SREBP2, liver X receptor (LXR), and ER stress signals. Downstream, GRAMD1C modulates plasma membrane cholesterol levels, which affect lipid raft integrity and signaling through AKT and downstream effectors of GPCR and RTK pathways. Additional pathway components such as CERT and STARD family proteins further coordinate intracellular lipid distribution.
In the A-549 lung adenocarcinoma background, GRAMD1C knockout disrupts cholesterol distribution and ER-PM communication, providing a physiologically relevant model for cancer cell biology. Lung adenocarcinoma cells exhibit a high demand for cholesterol to support membrane biogenesis and signaling, and GRAMD1C loss-of-function may reveal vulnerabilities in cholesterol?dependent processes. This model enables dissection of how altered cholesterol trafficking affects tumor cell proliferation, migration, and downstream signaling events such as AKT activation, frequently dysregulated in cancer.
Researchers can employ these GRAMD1C knockout polyclonal cells in a wide array of experimental systems, including filipin staining to visualize cholesterol distribution, immunofluorescence microscopy to assess ER-PM contact site integrity, and biochemical cholesterol quantification assays. The model is also suitable for transcriptional profiling via RT-qPCR of cholesterol synthesis genes, global lipidomics analyses, and western blotting to monitor signaling proteins such as phosphorylated AKT. Typical applications encompass the study of cholesterol trafficking and ER-PM contact sites, drug screening for cholesterol-related disorders, and investigations into lipid metabolism in lung adenocarcinoma. For further information or to request a custom variant of this product, please contact Ascent Research.
