GO:0060621 negative regulation of cholesterol import: Regulatory Mechanism, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0060621 (negative regulation of cholesterol import) describes any process that decreases the rate, frequency or extent of cholesterol import, the directed movement of cholesterol into a cell or organelle.
• Cholesterol import is mediated by transporters such as LRP-1 and is often coupled to steroidogenesis; its negative regulation can occur at the level of transporter expression, trafficking, or extracellular ligand availability.
• PCSK9 is a secreted regulator that can modulate cholesterol uptake and drive sterol-dependent metastatic organ choice in pancreatic cancer, illustrating how negative regulation of cholesterol import influences disease.
• In gastric cancer, cholesterol import and steroidogenesis biosignatures are associated with patient survival, highlighting the clinical relevance of this process.
• MicroRNAs such as miR-122 can regulate cholesterol metabolism, providing a mechanism for post-transcriptional negative regulation of cholesterol import.
• Experimental models for studying negative regulation of cholesterol import include CRISPR knockout of transporters, point mutations in regulatory domains, and overexpression of negative regulators.
Description
Cholesterol is an essential lipid for membrane integrity, hormone synthesis, and cell signaling. The directed movement of cholesterol into a cell or organelle, termed cholesterol import, is a tightly controlled process. GO:0060621, negative regulation of cholesterol import, encompasses any process that decreases the rate, frequency or extent of this import. This regulation is critical for maintaining cellular cholesterol homeostasis and preventing pathological lipid accumulation. Dysregulation of cholesterol import has been implicated in cancer, metabolic disorders, and neurodegenerative diseases. Understanding the molecular players and mechanisms that negatively regulate cholesterol import is therefore of broad biomedical importance. This article synthesizes published findings on the genes, pathways, and experimental approaches relevant to GO:0060621, providing a resource for researchers aiming to manipulate this process in disease models.
negative regulation of cholesterol import At A Glance
| GO ID | GO:0060621 |
|---|---|
| GO term | negative regulation of cholesterol import |
| Ontology | biological_process |
| Synonym | none |
| Major function | Decreases the rate, frequency or extent of cholesterol import into a cell or organelle |
| Related process | Cholesterol import (GO:0030301) |
| Regulatory direction | Negative |
| Example regulators | PCSK9, miR-122, LRP-1 |
| Disease relevance | Cancer, metabolic disorders, cardiovascular disease |
What Is GO:0060621?
GO:0060621 is a biological process term defined as any process that decreases the rate, frequency or extent of cholesterol import. Cholesterol import itself is the directed movement of cholesterol into a cell or organelle. Thus, negative regulation of cholesterol import includes mechanisms that reduce the uptake of cholesterol from the extracellular environment or from one cellular compartment to another. This regulation can be achieved by decreasing the activity or abundance of cholesterol transporters, altering membrane trafficking, or modulating signaling pathways that control lipid uptake.
Why Is negative regulation of cholesterol import Important in Cell Biology?
Negative regulation of cholesterol import is essential for cellular cholesterol homeostasis. Excessive cholesterol uptake can lead to lipid accumulation, membrane dysfunction, and altered cell signaling, contributing to diseases such as cancer and atherosclerosis. Conversely, insufficient cholesterol import can impair hormone synthesis and membrane function. Understanding how this process is negatively regulated provides insights into disease mechanisms and potential therapeutic targets. For example, PCSK9-mediated regulation of cholesterol uptake influences metastatic organ choice in pancreatic cancer, demonstrating the clinical impact of this process. In gastric cancer, cholesterol import and steroidogenesis biosignatures are predictive of patient survival, underscoring the prognostic value of this pathway.
• Maintains cellular cholesterol homeostasis by preventing excessive cholesterol uptake.
• Influences cancer progression and metastasis, as shown for PCSK9 in pancreatic cancer.
• Associated with patient survival in gastric cancer through cholesterol import and steroidogenesis biosignatures.
• Regulated by microRNAs such as miR-122, linking post-transcriptional control to cholesterol metabolism.
• Involved in glioblastoma pathobiology via LRP-1, a cholesterol transporter.
• Relevant to metabolic disorders and cardiovascular disease where cholesterol uptake is dysregulated.
• Provides targets for therapeutic intervention, e.g., PCSK9 inhibitors.
• Can be studied using CRISPR knockout, point mutation, and overexpression models.
• Impacts membrane lipid composition and cell signaling.
• Cross-talks with steroidogenesis pathways, affecting hormone production.
What Happens During negative regulation of cholesterol import?
Reduced transporter availability
In simple terms: The cell makes fewer cholesterol transporters or removes them from the surface, so less cholesterol can enter.
Negative regulation of cholesterol import can occur by decreasing the expression or surface localization of cholesterol transporters such as LRP-1. In glioblastoma, elevated LRP-1 expression is implicated in pathobiology, suggesting that its downregulation would negatively regulate cholesterol import. Similarly, PCSK9 can promote degradation of LDL receptors, reducing cholesterol uptake.
Extracellular ligand sequestration
In simple terms: Molecules outside the cell bind cholesterol or its carriers, preventing them from reaching transporters.
Secreted proteins like PCSK9 can bind to receptors and prevent cholesterol import. PCSK9 drives sterol-dependent metastatic organ choice in pancreatic cancer, indicating that its negative regulation of cholesterol import affects metastasis. Other extracellular factors may sequester lipoproteins, though specific mechanisms require further study.
Intracellular signaling cascades
In simple terms: Signals inside the cell can tell it to stop taking in cholesterol.
MicroRNAs such as miR-122 can regulate cholesterol metabolism. Delivery of miR-122 using a non-covalent peptide-based strategy regulated cholesterol metabolism, demonstrating post-transcriptional negative regulation. This suggests that miR-122 or similar microRNAs can decrease cholesterol import by targeting transporter mRNAs.
Membrane lipid remodeling
In simple terms: Changes in the membrane's fat composition can make it harder for cholesterol to enter.
In Saccharomyces cerevisiae, lipid droplets control the negative effect of non-yeast sterols in membranes under hypoxic stress, indicating that membrane lipid environment influences sterol import and its regulation. This highlights a conserved mechanism where lipid droplets buffer sterol levels and negatively regulate import.
Transcriptional control
In simple terms: The cell can turn off genes needed for cholesterol uptake.
Transcriptional repression of cholesterol transporter genes is a key mode of negative regulation. For instance, in gastric cancer, cholesterol import and steroidogenesis biosignatures are associated with survival, implying transcriptional programs that regulate these genes. However, specific transcription factors require further investigation.
Key Genes Involved in GO:0060621 negative regulation of cholesterol import
The following genes and proteins have been experimentally linked to the regulation of cholesterol import, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PCSK9 | Secreted protease that promotes LDL receptor degradation, reducing cholesterol uptake | Drives sterol-dependent metastatic organ choice in pancreatic cancer |
| LRP-1 | Cell surface receptor mediating cholesterol import | Elevated expression implicated in glioblastoma pathobiology |
| miR-122 | MicroRNA regulating cholesterol metabolism | Delivery regulates cholesterol metabolism via post-transcriptional mechanisms |
| SCAP | SREBP cleavage-activating protein, senses cholesterol | Not directly cited in provided references, but central to cholesterol homeostasis |
| INSIG | Insig proteins retain SCAP in ER when cholesterol is high | Not directly cited in provided references |
| HMGCR | Rate-limiting enzyme in cholesterol synthesis | Not directly cited in provided references |
| NPC1 | Intracellular cholesterol transporter | Not directly cited in provided references |
| NPC1L1 | Intestinal cholesterol absorption transporter | Not directly cited in provided references |
| ABCA1 | Cholesterol efflux pump | Not directly cited in provided references |
| ABCG1 | Cholesterol efflux pump | Not directly cited in provided references |
| SR-BI | HDL receptor mediating selective cholesterol uptake | Not directly cited in provided references |
| LDLR | LDL receptor mediating cholesterol import | Target of PCSK9 |
| Mce transporters | Mycobacterial lipid import systems | Architecture, regulation, lipid import in M. tuberculosis |
| Glutathione | Antioxidant involved in mitochondrial function | Linked to cholesterol metabolism? |
| CYP11A1 | Cholesterol side-chain cleavage enzyme, first step in steroidogenesis | Cholesterol import and steroidogenesis biosignature in gastric cancer |
| STAR | Steroidogenic acute regulatory protein, transports cholesterol into mitochondria | Cholesterol import and steroidogenesis biosignature in gastric cancer |
| CYP17A1 | Steroidogenic enzyme | Cholesterol import and steroidogenesis biosignature in gastric cancer |
How Is negative regulation of cholesterol import Regulated?
Negative regulation of cholesterol import is controlled at multiple levels. Extracellularly, PCSK9 binds to LDL receptors and promotes their degradation, reducing cholesterol uptake. Intracellularly, microRNAs such as miR-122 can downregulate genes involved in cholesterol metabolism. Membrane lipid composition and lipid droplets also modulate sterol import, as shown in yeast under hypoxic stress. Additionally, transcriptional programs responsive to sterol levels can repress transporter expression, though specific factors in human cells require further study. These regulatory layers ensure cholesterol homeostasis and can be hijacked in diseases like cancer.
negative regulation of cholesterol import and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PCSK9 | Pancreatic cancer metastasis | Knockout of PCSK9 in pancreatic cancer cell lines, metastasis assays |
| LRP-1 | Glioblastoma | Knockdown or knockout of LRP-1 in glioblastoma cells, proliferation and invasion assays |
| miR-122 | Cholesterol metabolism disorders | Overexpression of miR-122 in hepatocytes, cholesterol uptake assays |
| CYP11A1 | Gastric cancer | Knockout in gastric cancer cells, steroidogenesis and survival assays |
| Mce transporters | Tuberculosis | Knockout in M. tuberculosis, lipid import and infection assays |
Cancer metastasis
PCSK9 drives sterol-dependent metastatic organ choice in pancreatic cancer, demonstrating that negative regulation of cholesterol import influences where cancer cells metastasize. In glioblastoma, elevated LRP-1 expression is crucially implicated in pathobiology, suggesting that dysregulated cholesterol import contributes to tumor growth. Gastric cancer patient survival is associated with cholesterol import and steroidogenesis biosignatures, highlighting the prognostic importance of this pathway.
Metabolic disorders
Dysregulation of cholesterol import is linked to metabolic disorders. miR-122 regulates cholesterol metabolism, and its delivery can modulate circulating cholesterol levels. Although not directly cited, conditions such as atherosclerosis and fatty liver disease involve altered cholesterol uptake, and understanding negative regulation could provide therapeutic avenues.
Infectious disease
Mycobacterium tuberculosis utilizes Mce transport systems for lipid import, which are essential for its survival and pathogenesis. Negative regulation of these import systems could be a host defense mechanism, though direct evidence in the context of GO:0060621 is limited.
From negative regulation of cholesterol import-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does knockout of PCSK9 increase cholesterol import? | CRISPR knockout of PCSK9 in cancer cell lines, cholesterol uptake assays |
| Does point mutation in LRP-1 affect its negative regulation? | CRISPR point mutation in LRP-1 ligand-binding domain, binding assays |
| Can overexpression of miR-122 reduce cholesterol import? | Lentiviral overexpression of miR-122 in hepatocytes, cholesterol quantification |
| What is the effect of knocking out CYP11A1 on steroidogenesis? | CRISPR knockout of CYP11A1 in gastric cancer cells, steroid profiling |
| Does tagging endogenous LRP-1 with GFP alter its trafficking? | Knock-in of GFP tag at LRP-1 locus, live-cell imaging |
| Can CRISPR library screening identify new negative regulators of cholesterol import? | Genome-wide CRISPR knockout library in cells with fluorescent cholesterol analog, FACS sorting |
How to Study the negative regulation of cholesterol import Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout screen | Genes whose loss alters cholesterol import | Identify novel negative regulators |
| RNA-seq | Transcriptional changes in cholesterol transporters | Assess impact of candidate regulators |
| Proteomics | Protein abundance of import machinery | Validate post-transcriptional regulation |
| Fluorescent cholesterol uptake assay | Rate of cholesterol import | Functional validation of regulators |
| Mass spectrometry | Cholesterol and sterol species quantification | Measure lipid changes |
| miRNA mimic delivery | Post-transcriptional repression of target genes | Test miR-122 function |
| Immunofluorescence | Subcellular localization of transporters | Study trafficking |
| CRISPR point mutation | Effect of specific amino acid changes | Dissect regulatory domains |
CRISPR knockout screens
Genome-wide CRISPR knockout screens can identify genes whose loss increases cholesterol import, revealing negative regulators. For example, knocking out PCSK9 would be expected to increase cholesterol uptake, and such screens can uncover novel regulators.
Transcriptomics and proteomics
RNA-seq and proteomics can measure changes in expression of cholesterol transporters and related genes upon manipulation of candidate regulators. In gastric cancer, cholesterol import and steroidogenesis biosignatures were identified using such approaches.
Lipid imaging and quantification
Fluorescent cholesterol analogs (e.g., BODIPY-cholesterol) and mass spectrometry can quantify cholesterol import. These methods are essential to validate functional effects of negative regulators.
MicroRNA delivery and functional assays
Delivery of microRNAs such as miR-122 using peptide-based strategies can modulate cholesterol metabolism, and subsequent cholesterol uptake assays can confirm negative regulation.
How CRISPR Can Be Used to Study GO:0060621 negative regulation of cholesterol import
Knockout
CRISPR knockout of candidate negative regulators (e.g., PCSK9) can be used to assess whether loss of function increases cholesterol import. This approach is straightforward and can be applied in various cell lines to study the impact on cholesterol uptake and downstream phenotypes.
Point Mutation
Introducing point mutations in transporters or regulatory proteins (e.g., LRP-1) can reveal specific residues required for negative regulation. This is useful for dissecting binding interfaces or post-translational modification sites.
Knock-in
Knock-in of tags (e.g., GFP) or reporter genes at endogenous loci allows real-time tracking of protein localization and dynamics. For example, tagging LRP-1 can help visualize its trafficking and how negative regulators affect its surface levels.
Overexpression
Overexpression of negative regulators such as miR-122 or PCSK9 can be achieved via lentiviral vectors. This is useful to test sufficiency in reducing cholesterol import and to study downstream effects on cell behavior.
How EDITGENE Supports negative regulation of cholesterol import Research
Researchers studying negative regulation of cholesterol import-related genes often need to determine whether a candidate gene is causally involved in this process. EDITGENE provides a comprehensive suite of CRISPR services to enable such investigations, from gene knockout to precise point mutations and overexpression, ensuring rigorous and reproducible results.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of cholesterol import research.
Frequently Asked Questions About negative regulation of cholesterol import
What is GO:0060621?
GO:0060621 is the Gene Ontology term for negative regulation of cholesterol import, a biological process that decreases the rate, frequency or extent of cholesterol import into a cell or organelle.
What genes are involved in negative regulation of cholesterol import?
Key genes include PCSK9, LRP-1, miR-122, and steroidogenic enzymes such as CYP11A1, as supported by published studies.
How is cholesterol import negatively regulated?
It can be negatively regulated by reducing transporter expression, sequestering ligands, or via microRNAs like miR-122 that target cholesterol metabolism genes.
What diseases are associated with negative regulation of cholesterol import?
Diseases include pancreatic cancer metastasis, glioblastoma, gastric cancer, and metabolic disorders.
What experimental models are used to study negative regulation of cholesterol import?
Common models include CRISPR knockout cell lines, point mutations, overexpression of regulators, and genome-wide screens.
Can CRISPR be used to study negative regulation of cholesterol import?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression are all applicable to dissect this process.
What is the role of PCSK9 in cholesterol import?
PCSK9 promotes degradation of LDL receptors, thereby reducing cholesterol import and driving metastatic organ choice in pancreatic cancer.
How does miR-122 regulate cholesterol metabolism?
miR-122 can post-transcriptionally repress genes involved in cholesterol metabolism, leading to decreased cholesterol import.
What is the clinical significance of cholesterol import in gastric cancer?
Cholesterol import and steroidogenesis biosignatures are associated with patient survival in gastric cancer.
What methods measure cholesterol import?
Fluorescent cholesterol analogs, mass spectrometry, and uptake assays are commonly used to measure cholesterol import.
Conclusion
Negative regulation of cholesterol import (GO:0060621) is a critical biological process that maintains cholesterol homeostasis and influences disease progression. Key regulators such as PCSK9, LRP-1, and miR-122 have been implicated in cancer and metabolic disorders, providing potential therapeutic targets. Understanding the molecular mechanisms and employing advanced CRISPR models will further elucidate this process and aid in the development of novel interventions. EDITGENE offers comprehensive services to support such research endeavors.
References
- 1. Rademaker G et al.. 2025. PCSK9 drives sterol-dependent metastatic organ choice in pancreatic cancer.. Nature 643(8074):1381-1390 PMID: 40399683
- 3. N R S et al.. 2022. Elevated expression of cholesterol transporter LRP-1 is crucially implicated in the pathobiology of glioblastoma.. Front Neurol 13:1003730 PMID: 36267880
- 4. Petrisková L et al.. 2024. Lipid droplets control the negative effect of non-yeast sterols in membranes of Saccharomyces cerevisiae under hypoxic stress.. Biochim Biophys Acta Mol Cell Biol Lipids 1869(7):159523 PMID: 38866087
- 5. Chang WC et al.. 2017. Cholesterol import and steroidogenesis are biosignatures for gastric cancer patient survival.. Oncotarget 8(1):692-704 PMID: 27893427
- 6. Wang L et al.. 2013. Efficient delivery of miR-122 to regulate cholesterol metabolism using a non-covalent peptide-based strategy.. Mol Med Rep 8(5):1472-8 PMID: 24065042
- 8. Tan H et al.. 2026. Mce transport systems in Mycobacterium tuberculosis: architecture, regulation, lipid import, and translational perspectives.. J Bacteriol 208(8):e0022126 PMID: 42505103
