PDF G1S cell cycle regulated transcription and genome stability Biology Diagrams In the commonly accepted paradigm for control of the mammalian cell cycle, sequential cyclin-dependent kinase (CDK) and cyclin activities drive the orderly transition from G1 to S phase. However, recent studies using different technological approaches and examining a broad range of cancer cell types are challenging this established paradigm. An alternative model is evolving in which cell The accurate transition from G1 phase of the cell cycle to S phase is crucial for the control of eukaryotic cell proliferation, and its misregulation promotes oncogenesis.

Finally, a full accounting of how growth regulates the G1/S transition will also likely require a more detailed understanding of the mTOR signaling network and its mechanistic links to G1 control (Liu and Sabatini, 2020). We anticipate the nexus of cell size, growth, and the G1/S transition will be a very active area of research in the coming Strikingly, the cell-cycle phase targeted most frequently in multistep oncogenesis is the control of G1/S transition. This period includes the late-G1 commitment to replicate the genome and complete the cycle (the restriction point control), and the initiation of DNA replication, events regulated by the so-called `RB pathway'. On the basis of current knowledge, control of the G1/S phase transition is largely a matter of regulating a set of specific cyclin dependent kinase (CDK) activities. In mammalian cells, the G1/S specific CDK activities are composed of complexes between D type cyclins and either CDK4 or CDK6 and between cyclin E (and possibly cyclin A) and CDK2.

G1/S control and its deregulation in cancer Biology Diagrams
The G1/S transition is a stage in the cell cycle at the boundary between the G1 phase, in which the cell grows, and the S phase, during which DNA is replicated. [1] The cell cycle control system is biochemically based so that the proteins of the mitosis promoting factor

Notably, although the role of endogenous replication stress during the mother S phase provides well-established control of the daughter G1/S transition (19,22,23,40,45), a parallel contribution from ROS-mediated DNA damage arising from mother cell respiration has not been studied (to our knowledge), and may be an important avenue for future

Cancer takes many paths through G1/S Biology Diagrams
Cyclins regulate cell cycle timing by activating CDKs. Their levels fluctuate throughout the cycle, rising and falling in a phase-specific manner. Different cyclins are associated with distinct stages: cyclin D in G1, cyclin E at the G1/S transition, cyclin A in S and G2, and cyclin B in mitosis.
![A snapshot of F and the outgoing transitions of s [1,4] (i ranges over ... Biology Diagrams](https://www.researchgate.net/profile/Anthony-Lin-3/publication/224251031/figure/fig2/AS:393874213228551@1470918338791/A-snapshot-of-F-and-the-outgoing-transitions-of-s-1-4-i-ranges-over-1-2n.png)