Cyclin, CDKs, Cell Cycle Checkpoints – Lecture 4 Flashcards
control of cell cycle:
cell cycle is controlled in part by a class of proteins called ___
cyclins
control of cell cycle:
cell cycle is controlled in part by a class of ___ called cyclins
class of proteins
control of cell cycle:
___ is controlled in part by a class of proteins called cyclins
cell cycle
control of cell cycle:
cyclins (definition)
regulatory proteins that accumulate and degrade in a cell-cycle specific fashion
control of cell cycle:
as cell cycle progresses, cyclin protein concentration inside cell ___
increases
control of cell cycle:
w/o cyclin proteins, the cell cycle would ___
stop
cyclins regulate kinases:
kinases (definition)
protein enzymes that phosphorylate (add a phosphate group to) other molecules
cyclins regulate kinases:
phosphatases (definition)
enzymes that de-phosphorylate (remove a phosphate group from) other molecules
cyclins regulate kinases:
getting ___ affects the activity of a protein
phosphorylated
cyclins regulate kinases:
getting phosphorylated affects the activity of a ___
protein
cyclins regulate CDKs:
CDK (what does it stand for?)
cyclin dependent kinases
___ regulate CDKs
cyclins
cyclins regulate ___
CDKs
cyclins regulate CDKs:
___ are kinases that are inactive unless they are attached to a cyclin protein
CDKs
cyclins regulate CDKs:
CDKs are ___ that are inactive unless they are attached to a cyclin protein
kinases
cyclins regulate CDKs:
CDKs are kinases that are ___ unless they are attached to a cyclin protein
inactive
cyclins regulate CDKs:
CDKs are kinases that are inactive unless they are ___ to a cyclin protein
attached
cyclins regulate CDKs:
CDKs are kinases that are inactive unless they are attached to a ___
cyclin protein
cyclins regulate CDKs:
when ___ are activated by a cyclin, they can then phosphorylate their target proteins
CDKs
cyclins regulate CDKs:
when CDKs are ___ by a cyclin, they can then phosphorylate their target proteins
activated
cyclins regulate CDKs:
when CDKs are activated by a ___, they can then phosphorylate their target proteins
cyclin
cyclins regulate CDKs:
when CDKs are activated by a cyclin, they can then ___ their target proteins
phosphorylate
cyclins regulate CDKs:
when CDKs are activated by a cyclin, they can then phosphorylate their ___
target proteins
cyclins regulate CDKs:
cyclins activate CDKs –> phosphorylates target proteins:
ultimately, this results in changes w/in cell that are necessary to advance the ___
cell cycle
cyclins regulate CDKs:
cyclins activate CDKs –> phosphorylates target proteins:
ultimately, this results in changes w/in ___ that are necessary to advance the cell cycle
cell
cyclins regulate CDKs:
cyclins activate CDKs –> phosphorylates target proteins:
ultimately, this results in changes w/in cell that are necessary to ___ the cell cycle
advance
overview of cyclins, CDKs, and cell cycle:
cell cycle progresses
cyclin proteins accumulate in cell
cyclins activate CDKs
CDKs phosphorylate target proteins
phosphorylated target proteins advance cell cycle
cyclins are needed to proceed thru cell cycle ___
checkpoints
cyclins are needed to proceed thru ___ checkpoints
cell cycle
___ are needed to proceed thru cell cycle checkpoints
cyclins
cyclins are needed to ___ cell cycle checkpoints
proceed thru
cell cycle checkpoints (definition)
points during the cell cycle at which the progression of cell cycle can be stopped
what is purpose of cell cycle checkpoints?
prevent cell division during:
- improper environmental conditions
- incompletely replicated or damaged DNA
- misaligned chromosomes
what happens during cell division during improper environmental conditions:
probably would be lethal
what happens during cell division w/ incompletely replicated or damaged DNA:
probably would be lethal, or lead to uncontrolled cell division
what happens during cell division w/ misaligned chromosomes:
could also be lethal (unequal division of DNA)
cell cycle checkpoints:
there are ___ main cell cycle checkpoints
3
cell cycle checkpoints:
what are the 3 main cell cycle checkpoints
1) G1/S transition checkpoint
2) G2/M transition checkpoint
3) spindle checkpoint
G1/S transition checkpoint:
AKA start or restriction checkpoint
commitment to divide at all (regulated by cyclin/CDKs)
G2/M transition checkpoint:
commitment to proceed into mitosis (regulated by cyclin/CDKs)
spindle checkpoint
commitment to segregate the replicated DNA to opposite ends of the cell (anaphase)
regulated by APC (anaphase promoting complex)
cell cycle checkpoints:
APC:
anaphase promoting complex
regulates commitment to segregate replicated DNA to opposite ends of cell during anaphase in spindle checkpoint
not a cyclin/CDK complex
if cell fails the test at any checkpoint:
cell division is halted for repairs or cell death is induced (apoptosis)
apoptosis
cell death
cell cycle checkpoints:
G1/S (start or restriction) CP:
regulated by cyclin/CDKs
proper environmental conditions
sufficient nutritional state of cell
sufficient size of cell
cell cycle checkpoints:
G2/M (transition) CP:
regulated by cyclin/CDKs
is DNA completely replicated
no DNA damage
sufficient size of cell
cell cycle checkpoints:
spindle CP:
regulated by APCs (anaphase promoting complex)
are the chromosomes aligned properly for DNA segregation
cancer and cell cycle regulation:
genes that control the cell cycle are the most frequently mutated genes in all forms of ___
cancer
cancer and cell cycle regulation:
___ that control the cell cycle are the most frequently mutated genes in all forms of ___
genes
cancer and cell cycle regulation:
genes that ___ are the most frequently mutated genes in all forms of cancer
control the cell cycle
cancer and cell cycle regulation:
genes that control the cell cycle are the ___ in all forms of cancer
most frequently mutated genes
cancer and cell cycle regulation:
cells start the cell cycle when they shouldn’t
cells proceed to mitosis/cytokinesis when they shouldn’t
cells don’t die when they should (evasion of apoptosis)
cancer and cell cycle regulation:
cancer cells continue to ___ and become more and more difficult to treat
accumulate mutations
cancer and cell cycle regulation:
cancer cells continue to accumulate mutations and become more and more ___
difficult to treat
cancer and cell cycle regulation:
___ continue to accumulate mutations and become more and more difficult to treat
cancer cells
