The GRAMD1B Knockout HeLa Polyclonal Cells comprise a CRISPR/Cas9-mediated gene-disrupted human cell population in which GRAMD1B expression has been abrogated. This polyclonal knockout pool, derived from the HeLa cervical adenocarcinoma cell line, serves as a critical tool for interrogating intracellular cholesterol trafficking mechanisms. By eliminating functional GRAMD1B, researchers can assess its role in non-vesicular lipid transfer at endoplasmic reticulum?Cplasma membrane contact sites.
HeLa cells are an immortalized epithelial line originating from a human cervical adenocarcinoma, classified as HPV18-positive. These cells are extensively used in oncology, signal transduction, and cell biology studies due to their robust growth and well-characterized genetic background. Their continued use provides a consistent platform for examining the molecular underpinnings of cholesterol metabolism and associated pathologies.
GRAMD1B, also known as Aster-B, encodes a lipid-transfer protein that facilitates ATP-independent cholesterol transport from the plasma membrane to the endoplasmic reticulum (ER). Its activity is regulated by cellular cholesterol levels and integrates upstream signals from SREBP2 and LXR. At membrane contact sites, GRAMD1B interacts with VAPA, VAPB, and OSBP to coordinate lipid exchange. This process directly modulates SREBP2 cleavage, leading to transcriptional control of LDL receptor expression, cholesterol esterification, and mTORC1 activation. Key components of the GRAMD1B signaling network include SCAP, SREBP2, and VAPA, which together govern cellular cholesterol homeostasis.
In the HeLa cell context, loss of GRAMD1B perturbs cholesterol redistribution, likely causing ER cholesterol depletion and consequent dysregulation of SREBP2-dependent transcription. Because HPV-driven cancers often exhibit altered lipid metabolism, this polyclonal knockout model enables the study of cholesterol dependency in cervical adenocarcinoma, offering insights into how membrane contact site dysfunction contributes to oncogenic processes and metabolic reprogramming.
This product supports a wide range of experimental approaches, including filipin staining for cholesterol localization, LDL uptake and cholesterol esterification assays, western blotting for SREBP2 processing, RT-qPCR for SREBP target genes, confocal microscopy of GRAMD1B and interacting partners, and lipidomic profiling. It is ideally suited for cholesterol trafficking studies, SREBP pathway dissection, membrane contact site research, and drug screening for metabolic disorders such as atherosclerosis and metabolic dysfunction-associated steatotic liver disease. For more information, please contact Ascent Research.
