Misc
All the following statements about cyclins are true except
Cyclins do not have enzymatic domains.
Cyclins may be degraded by polyubiquitylation and targeting to proteasomes.
Cellular concentration of specific cyclins is stable throughout the cell cycle
Cyclins bind to and activate specific kinase partners.
All the following statements about cyclins are true except
Cyclins do not have enzymatic domains.
Cyclins may be degraded by polyubiquitylation and targeting to proteasomes.
Cellular concentration of specific cyclins is stable throughout the cell cycle
Cyclins bind to and activate specific kinase partners.
Which of the following is a direct substrate of APC?
Securin
Mitotic cyclin
Cohesin
Mitotic cdk
Both A and B
Which of the following is a direct substrate of APC?
Securin
Mitotic cyclin
Cohesin
Mitotic cdk
Both A and B
You are studying cell cycle regulation in mitotic mammalian cells. What result would you predict when you add the following to cells that are about to enter M-phase.
Adding a drug that inhibits mitotic-CDK (M-CDK)
The cels wil not have activated APC/C.
The cells will not condense their replicated chromatin i n t o heterochromatin
The cels wil remain i n G2 phase.
Both A and B
All of the above
You are studying cell cycle regulation in mitotic mammalian cells. What result would you predict when you add the following to cells that are about to enter M-phase.
Adding a drug that inhibits mitotic-CDK (M-CDK)
The cels wil not have activated APC/C.
The cells will not condense their replicated chromatin i n t o heterochromatin
The cels wil remain i n G2 phase.
Both A and B
All of the above
Entry into Go can be triggered by nutrient limitation, DNA damage, & also prior to differentiation
True
False
Entry into Go can be triggered by nutrient limitation, DNA damage, & also prior to differentiation
True
False
A loss of function in p53 is consistent with which of the following scenarios?
a p53 that can not be phosphorylated and stabilized
a p53 that can not be polyubiquylated and degraded i n proteasomes
a p53 that constitutively binds t o regulatory regions of p21 gene
a p53 that constitutively binds to regulatory regions of apoptotic genes
All of the above
A loss of function in p53 is consistent with which of the following scenarios?
a p53 that can not be phosphorylated and stabilized
a p53 that can not be polyubiquylated and degraded i n proteasomes
a p53 that constitutively binds t o regulatory regions of p21 gene
a p53 that constitutively binds to regulatory regions of apoptotic genes
All of the above
Which one of the following is due to activation of APC/C.
Attachment of sister chromatids to each other by cohesin proteins.
Polyubiquitylation of mitotic cyclin dependent kinase (M-CDK)
Proteasomal degradation of M-cyclin
Both A & B
Al of the above
Which one of the following is due to activation of APC/C.
Attachment of sister chromatids to each other by cohesin proteins.
Polyubiquitylation of mitotic cyclin dependent kinase (M-CDK)
Proteasomal degradation of M-cyclin
Both A & B
Al of the above
You are studying cell cycle regulation in mitotic mammalian cells. What result would you predict when you add the following to cells that are about to enter M-phase.
Adding an actin filament assembly inhibitor drug
Nuclear lamins will not disassemble and nuclear envelope wil not vesicularize
Contractile rings will not form and cells will not initiate cytokinesis
Spindle fibers will not attach to sister chromatid kinetochores, and cells wil not reach metaphase.
Both A and B
Al of the above.
You are studying cell cycle regulation in mitotic mammalian cells. What result would you predict when you add the following to cells that are about to enter M-phase.
Adding an actin filament assembly inhibitor drug
Nuclear lamins will not disassemble and nuclear envelope wil not vesicularize
Contractile rings will not form and cells will not initiate cytokinesis
Spindle fibers will not attach to sister chromatid kinetochores, and cells wil not reach metaphase.
Both A and B
Al of the above.
DNA damage is sensed by kinases that become active when they bind to free internal ends of chromosomal DNA and lead to stabilization of p53.
True
False
DNA damage is sensed by kinases that become active when they bind to free internal ends of chromosomal DNA and lead to stabilization of p53.
True
False
Which one of the following induces entry into Go in cells?
Loss of function mutation in inhibitory proteins such as p21
Gain of function mutation in G1-CDK
Exposing cells to DNA damaging radiation such as X-rays or UV-rays
Increasing t e amino acid concentration of the growth media of the cells.
None of the above.
Which one of the following induces entry into Go in cells?
Loss of function mutation in inhibitory proteins such as p21
Gain of function mutation in G1-CDK
Exposing cells to DNA damaging radiation such as X-rays or UV-rays
Increasing t e amino acid concentration of the growth media of the cells.
None of the above.
You are studying cell cycle regulation in mitotic mammalian cells. What result would you predict when you add the following to cells that are about to enter M-phase.
Adding a proteasome inhibiting drug
Mitotic-CDK activity will remain high and will not diminish through M-phase
The cells will progress through first half of mitosis and then get stuck at metaphase.
Mitotic Cyclin concentration will remain high and will not drop.
Both A and B
All of the above.
You are studying cell cycle regulation in mitotic mammalian cells. What result would you predict when you add the following to cells that are about to enter M-phase.
Adding a proteasome inhibiting drug
Mitotic-CDK activity will remain high and will not diminish through M-phase
The cells will progress through first half of mitosis and then get stuck at metaphase.
Mitotic Cyclin concentration will remain high and will not drop.
Both A and B
All of the above.
Rb protein binds E2F transcription regulatory protein and keeps it inactive until an extracellular mitogen activates receptor tyrosine kinase signaling.
True
False
Rb protein binds E2F transcription regulatory protein and keeps it inactive until an extracellular mitogen activates receptor tyrosine kinase signaling.
True
False
Which one of the following is NOT seen during apoptosis
Increased protein degradation in lysosomes and proteosomes
Chromatin fragmentation
Activation of a Caspase cascade which are proteolytic enzymes
Formation of apoptotic bodies
Both C and D .
Which one of the following is NOT seen during apoptosis
Increased protein degradation in lysosomes and proteosomes
Chromatin fragmentation
Activation of a Caspase cascade which are proteolytic enzymes
Formation of apoptotic bodies
Both C and D .
You have a mutant human cell line that successfully goes through mitosis, but during mitosis does not breakdown its nuclear envelope. Based on what you have learned, the most likely and most specific molecular basis is:
• Your cel line has a loss of function mutation in its M - C D K
• Your cell line has mutant lamins that can not be phosphorylated by M-CDK
• Your cel line has mutant lamins that c a n not form the nuclear lamin mes hw ork.
• Both A and B
• Al of the above
You have a mutant human cell line that successfully goes through mitosis, but during mitosis does not breakdown its nuclear envelope. Based on what you have learned, the most likely and most specific molecular basis is:
• Your cel line has a loss of function mutation in its M - C D K
• Your cell line has mutant lamins that can not be phosphorylated by M-CDK
• Your cel line has mutant lamins that c a n not form the nuclear lamin mes hw ork.
• Both A and B
• Al of the above
Many genes involved in cancer are mutated versions of genes involved in the cell cycle control system.
True
False
Many genes involved in cancer are mutated versions of genes involved in the cell cycle control system.
True
False
Intrinsic apoptotic pathway is activated when degenerating/damaged mitochondria leach cytochrome C molecule into the cytoplasm
True
False
Intrinsic apoptotic pathway is activated when degenerating/damaged mitochondria leach cytochrome C molecule into the cytoplasm
True
False