Related Experiment Video
Updated: Apr 18, 2026
08:30
Author Spotlight: Visualizing Single-Stranded DNA During DNA Repair for Therapeutic Insights
Published on: December 22, 2023
3.7K
Purinosome formation as a function of the cell cycle
Chung Yu Chan1, Hong Zhao2, Raymond J Pugh2
1Departments of Engineering Science and Mechanics and.
Summary
Purinosome formation, a key process in purine synthesis, is closely linked to the cell cycle. This study found purinosomes are most abundant in G1 phase cells, with variations observed between different cell models.
Area of Science:
- Biochemistry
- Cell Biology
- Molecular Biology
Background:
- The de novo purine biosynthetic pathway is essential for cellular function.
- Enzymes in this pathway can form a multienzyme complex called the purinosome under purine-depleted conditions.
- Purinosomes are important in mammalian cancer cells, but their cell cycle dependency is not fully understood.
Purpose of the Study:
- To investigate the relationship between the cell cycle and purinosome formation.
- To compare purinosome formation across different cell cycle phases in distinct cell models.
Main Methods:
- Time-lapse fluorescence microscopy was employed to visualize purinosome formation.
- Cell synchronization techniques were used to isolate specific cell cycle phases.
- Two cell models, HeLa and HGPRT-deficient fibroblasts, were utilized.
Main Results:
- HeLa cells showed significantly higher purinosome formation in the G1 phase.
- HGPRT-deficient fibroblasts also exhibited peak purinosome formation in G1 phase.
- Elevated purinosome levels were also detected in S and G2/M phases in fibroblasts, suggesting cell-model-specific variations.
Conclusions:
- Purinosome formation is closely related to the cell cycle.
- Differences in purine biosynthetic mechanisms contribute to variations in cell cycle-dependent purinosome formation between cell models.
Related Concept Videos
02:55The Nucleolus
10.8K
The nucleolus is the most prominent substructure of the nucleus. When it was first discovered, it was considered to be an isolated organelle that forms fibrils and granules. In 1931, the relationship between the nucleolus and chromosomes was first described by Heitz. He observed that the appearance and size of nucleolus varies depending on the stage of the cell cycle. He also noticed constricted regions on different chromosomes clustered together at definite cell cycle stages. These regions,...
10.8K
01:34Nuclear Protein Sorting
6.7K
Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell.
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
6.7K
01:23Negative Regulator Molecules
39.2K
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
39.2K
02:36Cells Coordinate Growth and Proliferation
5.4K
Cell size is a significant factor impacting cellular design, function, and fitness. There exists some internal coordination by which cells double their masses before division, thus, achieving homeostasis. Coordination between cell growth and proliferation depends on the checkpoints in between cell cycle phases. Loss of coordination or failure in the checkpoint mechanism can drive the cell to uncontrolled growth and loss of cellular function. Like dividing cells that coordinate cellular growth,...
5.4K
01:45Positive Regulator Molecules
137.4K
To consistently produce healthy cells, the cell cycle—the process that generates daughter cells—must be precisely regulated.
137.4K
02:39Positive Regulator Molecules
7.1K
Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.
7.1K