Cell cycle regulation ppt Biology Diagrams A newly identified cell-cycle master regulator protein, GcrA, together with the CtrA master regulator, are key components of a genetic circuit that drives cell-cycle progression and asymmetric polar morphogenesis in Caulobacter crescentus.The circuit drives out-of-phase temporal and spatial oscillation of GcrA and CtrA concentrations, producing time- and space-dependent transcriptional Cell cycle progression is controlled by regulatory proteins that act as molecular switches, responding to internal and external signals to either promote or halt division. Among the most significant regulators are cyclins, cyclin-dependent kinases (CDKs), and cell cycle inhibitors. Cyclins. Cyclins regulate cell cycle timing by activating CDKs.
Representation of the cell cycle as being composed of three linear and repetitive series of S phase (S), mitosis (M) and cytokinesis (C). (A) In this simplified model, the three series of events would be regulated individually and coupled to cell growth in an unknown manner.(B) In reality, they are coupled to one another more directly through checkpoint mechanisms. The second approach to understanding cell cycle regulation was the genetic analysis of yeasts, pioneered by Lee Hartwell and his colleagues in the early 1970s.Studying the budding yeast Saccharomyces cerevisiae, these investigators identified temperature-sensitive mutants that were defective in cell cycle progression.The key characteristic of these mutants (called cdc for cell division cycle Disruptions in these regulatory mechanisms can lead to diseases such as cancer and genetic disorders, highlighting their biological significance. where genes involved in cell cycle regulation and apoptosis may be improperly silenced or activated. Histone methylation also affects chromatin structure but in a more context-dependent manner
Topology and Control of the Cell Biology Diagrams
The reciprocal regulation of CtrA and GcrA at a transcriptional level has been suggested to form an oscillating genetic circuit that drives the cell cycle 8,12.
Notably, a synthetic gene circuit consisting of a tunable band-pass filter (Fig. 4Db) regulating NGN3 expression synchronized to cell stage-specific PDX1 expression and ฮฒ-cell-specific MAFA An emerging and critical feature of designing circuits for these applications is their genetic stability. 41 Introducing gene circuits into host cells can impose a fitness cost by creating a metabolic or resource burden or from expression of a toxic protein product. 42, 43, 44 Cells harboring mutations that abrogate circuit function can
