1. Regulation of the Cell Cycle
Chapter 10.3 (p )
HHMI: The Eukaryotic Cell Cycle and Cancer
Regulation of the Cell Cycle

3. External Regulators Cell-Cell Recognition
Surface proteins in direct contact
Inhibits cell division

4. External Regulators Growth Factors
Molecules that bind to surface receptor proteins
Stimulate cell division

5. Stimulate cell cycle when together!
Internal Regulators
CDKs
Enzymes that “activate” other proteins by attaching a phosphate group
Always present in cell
Cyclins
Proteins that bind to CDKs
Fluctuate throughout cell cycle
Concentration
Type
Stimulate cell cycle when together!

6. Internal Regulators P53 & BRCA1 MAD
Stalls cell from progressing to next phase
DNA can be repaired
If damage cannot be fixed
Apoptosis
Prevents cell from progressing to anaphase when chromosomes are not properly attached to spindle fibers
Inhibit cell cycle!

7. Cancer Caused by The body’s loss of control over the cell cycle
Stimulation of cycle
Cells forgetting to die
Accumulation of cells = tumor

8. Characteristics of Cancer
Hyperplasia: uncontrolled cell division
Dedifferentiation: loss of specialized functions of normal cells
Invasiveness: ability to grow and spread into neighboring tissue
Angiogenesis: promote the formation of blood vessels for nourishment
Metastasis: cells can detach and travel via blood to other areas of the body, starting new tumors