Week 2 Flashcards
what is G1 phase
synthesis of RNA and
proteins, preparation for S phase
what is s phase
DNA synthesis and
chromosome replication
what is G2 phase
continued growth,
preparation for M phase
what is M phase
mitosis occurs, with
segregation of chromosomes into daughter cells
what is G0 phase
exit from the cell cycle; state of being for all differentiated cells in the body
what are cyclins
the regulatory subunits
that control cell-cycle events
what are CDKs
catalytic subunit;
phosphorylate proteins
associated with a particular Cyclin-CDK complex
what is a kinase
catalyze the transfer of a
phosphate from ATP to a OH group (Serine Threonine, or Tyrosine side chains) on a target protein
what is a phosphatase
catalyze the
dephosphorylation of the protein
what is a CDKI
inhibitor of CDK
What is inhibitory phosphorylation
CDK is phosphorylated and becomes inactive even with CDK cyclin complex
what is a inhibitory kinase for CDK
wee 1
what is a excitatory phosphatase
cdc 25
EGFR pathway activates what transcription factor
Myc
what gene does myc transcribe
cyclin D gene
cyclin D-CDK phosphorylates and inactivates what protein
Rb
Once Rb is phosphorylated what happens after
It releases E2F and allows it to transcribe S-phase genes
what is the restriction point
G1/S phase
What is regulation of the restriction point
Growth factors must be
continually provided at
high levels to accumulate
enough Cyclin D to drive
past the restriction point
what are some tumor suppressors
Rb, p53, CDKis
what is Knudsons’s two hit hypothesis
tumor suppressor genes function like recessive genes
what is dna damage regulated by
p53 and ATM
how is unreplicated dna controlled
ATR
what is ATM
kinase that helps to repair double DNA strand repair, tumor suppressor, activates p53
what is ataxia telangiectasia
atm is mutated, autosomal recessive disorder
what is ATR
kinase activated by DNA damage and single stranded DNA, leads to activation of p53
what is p53
transcription factor that acts as a tetramer, 4 molecules together to bind dna
how is p53 regualted
MDM2, a ubiquitin ligase, targets p53 for degradation, in dna damage MDM2 is inhibited and p53 increases
what genes do p53 transcribe
CDKis, causes halt in cell cycle and replication
what is Li-Fraumeni Syndrome
autosomal dominant, one p53 allele is mutated decreased ability to bind dna
what is TGFBR
serine/theronine kinase, heterodimer, some of its mediators inhibit growth of epithelial cells (depends on the cell)
Where is TGFBR stored and released
released from wbc and stored latent in the ECM
what is the 1st step in the TGFBR pathway
ligand binds to receptor and receptor dimerizes
what is the 2nd step in the TGFBR pathway
receptor phosphorylates the SMAD transcription factors and the dimerize
what is the 3rd step in the TGFBR pathway
SMADs expose their nuclear localization signal and go tot the nucleus
what is the 4th step in the TGFBR pathway
SMAD’s interact with transcriptional cofactors to regulate transcription (depends on cell)
