👉 Arrest biology refers to the complex series of cellular and molecular events that occur when a cell is stopped from dividing, typically in response to external signals or internal damage. This process, known as cell cycle arrest, involves the activation of checkpoint mechanisms that halt the cell cycle at specific points, such as the G1/S, G2/M, or intra-S phases. Key players include cyclin-dependent kinases (CDKs) and their inhibitors (CKIs), which regulate the progression through these checkpoints. For instance, during G1 arrest, the p53 tumor suppressor protein is activated to induce cell cycle inhibitors like p21, preventing the cell from entering S phase if DNA damage is detected. Similarly, in G2/M arrest, the spindle assembly checkpoint ensures chromosomes are properly aligned before mitosis. These arrest mechanisms are crucial for maintaining genomic stability and preventing the propagation of damaged cells, which could lead to cancer or other diseases.
