The cell cycle is the ordered series of events that results in the duplication of one eukaryotic cell into two identical daughter cells. Key regulators of the cell cycle include cyclins and cyclin-dependent kinases (Cdks). Cyclins associate with specific phases of the cell cycle and activate Cdks, which drive cell cycle events by phosphorylating target proteins. A famous example is maturation-promoting factor (MPF), which is a Cdk bound to M cyclin that promotes M phase events like nuclear envelope breakdown. Proper regulation and control of the cell cycle is important for normal growth and replacement of cells, while loss of control can lead to cancer.

1. CELL CYCLE
SUBMITTED BY SUBMITTED TO
PRASHANT SHARMA Dr. MONIKA ASTHANA
BIOTECHNOLOGY INCHARGE
DEPARMENT OF
BIOTECHNOLOGY

2. Cell Cycle
The cell cycle is the
ordered series of events
required for the faithful
duplication of one
eukaryotic cell into
two genetically identical
daughter cells.

4. CELL CYCLE

11. CELL CYCLE
REGULATORS

12. Cyclins
• Cyclins are among the most important core cell cycle
regulators. Cyclins are a group of related proteins, and
there are four basic types found in humans and most
other eukaryotes: G1 cyclins, G1/S cyclins, S cyclins,
and M cyclins.
• As the names suggest, each cyclin is associated with a
particular phase, transition, or set of phases in the cell
cycle and helps drive the events of that phase or
period. For instance, M cyclin promotes the events of
M phase, such as nuclear envelope breakdown and
chromosome condensation

15. Cyclin-dependent kinases
• In order to drive the cell cycle forward, a cyclin must
activate
or inactivate many target proteins inside of the cell.
Cyclins drive the events of the cell cycle by partnering
with a family of enzymes called the cyclin-dependent
kinases (Cdks).
Alone Cdk is inactive, but the binding of a cyclin
activates it, making it a functional enzyme and
allowing it to modify target proteins.

18. Modes of CDK Regulation

20. Maturation-promoting factor (MPF)
• A famous example of how cyclins and Cdks work
together to control cell cycle transitions is that of
maturation- promoting factor (MPF). The name dates
back to the 1970s, when researchers found that cells
in M phase contained an unknown factor that could
force frog egg cells (stuck in G2 phase) to enter M
phase. This mystery molecule, called MPF, was
discovered in the 1980s to be a Cdk bound to its M
cyclin partner

22. MPF
Regulation

26. Significance of Cell Cycle
1. In multicellular organisms, the "Cycling Type" of
cells (dividing cells) help in reproduction, growth,
and replacement of dead cells , healing of wouds,
etc.
2. The interphase allows time for synthesis and growth
of dividing cells.
3. Properly controlled and regulated cell cycle results in
normal and proportionate growth of organisms.
4. Loss of control over the cell cycle can lead to
cancerous growth.