The GRAMD1C Knockout Jurkat Polyclonal Cells comprise a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Jurkat human leukemic T-cell line, engineered for disruption of the GRAMD1C gene. This product is provided as a polyclonal mixture of edited cells, reflecting a broad sampling of CRISPR-mediated gene disruptions without single-cell clone selection. The knockout model enables loss-of-function studies of GRAMD1C, a key cholesterol sensor and mediator of non-vesicular cholesterol transport at endoplasmic reticulum?Cplasma membrane (ER-PM) contact sites. By ablating GRAMD1C function, researchers can interrogate its roles in cholesterol trafficking, ER-PM communication, and downstream signaling pathways in a well-characterized T-lymphocyte background.
Jurkat cells, originally isolated from the peripheral blood of a patient with acute T-cell leukemia, are a widely adopted model for investigating T-cell receptor (TCR) signaling, apoptosis, and lymphocytic biology. These suspension cells grow robustly in culture and recapitulate essential features of T-cell activation, including calcium flux, cytokine production, and lipid raft reorganization. Their use in cholesterol research is particularly relevant given the critical influence of membrane cholesterol on TCR nanoclustering and signal initiation. The GRAMD1C knockout polyclonal population retains the core characteristics of the parental Jurkat line, providing a consistent host for dissecting sterol-dependent lymphocyte functions.
GRAMD1C encodes a sterol-binding protein that localizes to ER-PM junctions, where it senses plasma membrane cholesterol levels. Upon cholesterol depletion, GRAMD1C undergoes a conformational change that promotes its association with VAPA and VAPB, tethering the ER and PM and facilitating the non-vesicular transfer of cholesterol from the plasma membrane to the ER. This transport event regulates the proteolytic activation of sterol regulatory element-binding protein 2 (SREBP2), a master transcription factor controlling cholesterol biosynthesis and uptake. Downstream targets of SREBP2 include HMGCR and LDLR, key genes in cholesterol metabolism. Additionally, GRAMD1C interacts with oxysterol-binding protein (OSBP) and may cooperate with NPC1 to orchestrate lipid distribution. The knockout thus disrupts a central node connecting cellular cholesterol sensing, ER-PM crosstalk, and transcriptional control of lipid homeostasis.
In Jurkat T cells, disruption of GRAMD1C is expected to perturb cholesterol distribution, potentially impacting lipid raft assembly and TCR signal transduction. Given that membrane cholesterol content modulates the lateral mobility and clustering of TCR complexes, loss of GRAMD1C may alter early activation events, including calcium mobilization and IL-2 production. The interaction with VAPA/VAPB and SREBP2 cleavage provides a direct molecular link between GRAMD1C and the transcriptional machinery governing lipid metabolism. This knockout model is therefore highly suited for examining how cholesterol trafficking dysregulation affects lymphocyte proliferation, apoptosis, and leukemic cell survival, offering insights into metabolic vulnerabilities in T-cell malignancies.
This GRAMD1C knockout polyclonal cell product is a versatile tool for mechanistic investigations of non-vesicular cholesterol transport, ER-PM contact site biology, and lipid-mediated signaling in a human T-cell context. Applications include filipin staining for cholesterol visualization, quantitative cholesterol transport assays, western blotting for SREBP2 processing, RT-qPCR profiling of HMGCR and LDLR expression, and immunofluorescence analysis of GRAMD1C-interacting proteins. Additionally, the cells can be employed in lipidomics studies, calcium flux measurements, and IL-2 secretion assays to assess functional outcomes of altered cholesterol homeostasis. The product is also suitable for screening small-molecule modulators of cholesterol trafficking. For further details, please contact Ascent Research.
