wee 1
protein kinase responsible in phosphorylation
cdc 25
dephosphorylate the sites through phosphatase function
cyclin protein also directs the CDK to specific target proteins
How do different cyclin-CDK complexes trigger different cell-cycle events?
CDK inhibitor proteins (CKIs)
-responsible for inhibitory phosphorylation
protects from DNA damage for generations
rise and fall of cyclin cycles is the primary control
anaphase promoting complex or cyclosome (APC/C)
allows for occurrence of anaphase
key regulator of metaphase to anaphase transition
member of ubiquitin family of enzymes
CDC 20
what activates APC?
ubiquitin
usually a signal for degradation
APC polyubiquitylate
targets proteins for destruction via proteasome
securin
holds sister chromatid pairs together
destroys the securin so that sister chromatids can separate
what happens when polyubiquitylate binds to securin?
SCF
-ubiquitin ligase -ubiquitinates (break down) CK 1 proteins late in G1, and G1/S, cyclins in early of S phase
CDC6 and CDT1
what proteins collaborate with ORC to load inactive DNA helicase around the DNA next to the origin
s-Cdk
what triggers origin activations by phosphorylating initiator proteins
CDC 6
what is needed to prevent the assembly of new preRC until the end of mitosis
increase the production of histone proteins
what happens during S phase to provide raw material needed for packaging?
cohesin
-facilitates the attachment of 2 sister chromatids
deposited at many locations along the length of each sister chromatid
forms ring like structure around the two sister chromatids
ring-like
what structure does cohesin form around the two sister chromatids?
sister chromatids
what helps organize DNA until it is time to separate?
chromosome condensation
large scale reorganization of the intertwined sister chromatids into compact rod-like structures
M-cyclin and M-Cdk
what accumulates prior to Mphase
CDC activation kinase (CAK)
what tries to activate Cdk1 but is not able to because of Wee1
Wee 1
inhibits Cdk1 through inhibitory phosphorylation sites
Cdc 25
phosphatase removes the inhibitory phosphates on M-Cdk1-cyclin
Wee 1
inhibits positive feedback loop that allows for M-Cdk1-cyclin activity to increase
positive feedback
does not shut itself down unless there is nothing left (forest fire for example)
negative feedback
something in pathway that stops it (inhibition)
-positive feedbaclk loop that uses M-cdk-cyclin to activate Cdc25
S-Cdk also activates Cdc25
what activated Cdc 25?
M-Cdk-Cyclin
enough of what will inhibit inhibition by activation of Cdc25?
condensin
sister chromatid resolution depends on this 5 subunit protein complex
phosphorylation by M-Cdk
what is condensin stimulated by?
chromosome
what is easier to separate? chromosomes or chromatin?
green
are the microtubules green or orange?
orange
are the chromosomes orange or green?
prophase
what phase condenses into chromosomes and have the mitotic spindle formation at the centrosomes?
prometaphase
What phase causes a sudden nuclear envelope breakdown, and have the chromosomes attach to the spindle microtubules by their kinetochore?
metaphase
What phase causes the chromosomes to align at the equator at the spindle where the microtubules attached at the kinetochores at the sister chromatids to opposite poles of the spindle?
anaphase
What phase causes the sister chromatids to synchronously separate to form two daughter chromosomes, and pull them towards the spindle poles to have chromosome segregation?
contractile ring
What separates 2 cells with the use of actin and myosin to form a cleavage furrow during telophase?
telophase
What phase has the two sets of daughter chromosomes that arrive at the poles of the spindle and decondense, a new nuclear envelope reassembles, and uses the contractile ring to help begin the contraction of the cell and cytoplasm?
cytokinesis
what phase of the cell cycle has the cytoplasm divide in two by the contractile ring with the actin and myosin filaments to pink the cell in two to form two new cells with their separate nucleus?
negative
What charge are the ends of the microtubules?
interpolar microtubule
what overlaps with plus ends of other microtubules?
kinetochore microtubule
what has the positive ends that attach to sister chromatid pairs?
astral microtubule
what radiates outward from the poles helping to position the mitotic spindle?
centrosome
What is it when the spindle pole is focused at protein organelle?
centrioles
what do centrosomes contain a pair of?
kinesin and dynein
what two proteins are the microtubule dependent motor proteins?
kinesin
move toward the plus end of MT
dynein
move toward the minus end of MT
kinesin-5
-two motor domains -interact with plus ends of antiparallel MT
2 motor domains will pus the 2 MT past each other toward the spindle poles
kinesin-14
-minus end directed motors, with single motor domain
can cross-link antiparallel MT and pull the poles together
kinesin-4 and kinesin-10
-chromokinesins
plus end directed motors that associate with chromosome arms and push the chromosome away from the pole
dynein
-minus end directed motors
organize MT at various locations in the cell
kinesin 14 and kinesin-5
what are interpolar microtubules?
p 53
tumor suppressor that inhibits the cell cycle
ATM/ATR
-related protein kinases
associated with the site of damage
phosphorylate target proteins
p 21
what also helps inhibit the cell cycle with p 53?
mdm2
ubiquitin ligase
ataxia telangiectasia
caused by defect in ATM
transcription
DNA to RNA
Guanine cap
what helps the ribosome bind to mRNA?
poly A tail
what helps mRNA leave the nucleus?
Initiation, Elongation, Termination
3 steps of transcription
no
does pre-mRNA interact with ribosomes?
translation
RNA to protein
single stranded
Is RNA single stranded or double stranded?
uracil
Does RNA have uracil or thymine?
because it is single stranded
why does RNA fold on itself with H-bonds?
ribose
what sugar does RNA have?
no
does RNA require an RNA primer?
adenine
what does uracil usually bind to with 2 hydrogen bonds?
RNA polymerase
what catalyzes formation of phosphodiester bonds that link the nucleotides together to form a linear chain? It also helps with unwinding the DNA helix to help with RNA formation.
mRNA (messenger)
what RNA codes for proteins?
rRNA (ribosomal)
what RNA forms the basic structure of the ribosome and catalyze protein synthesis?
tRNA (transfer)
what RNA has central to protein synthesis as adaptors between mRNA and amino acids
snRNA (small nuclear)
what RNA functions in a variety of nuclear processes, including the splicing of pre-mRNA?
siRNA (small interfering)
what RNA turns off gene expression by directing the degradation of selective mRNAs and the establishment of compact chromatin structures
sigma factor
what helps with the promotion of bacterial transcription?
bacterial initiation
What helps the cell regulate which proteins are to be produced and at what rate in bacteria?
promoter
what special sequence of nucleotides indicates the starting point for RNA synthesis?
terminator
-chain elongation continues until polymerase hits this sequence
polymerase halts, releases newly made RNA molecule and DNA
Bacteria to string of AT nucleotide pairs
consensus nucleotide sequence
-common nucleotide found within a sequence
recognized by sigma factor
can have variation but all contain these related sequences
multiple
how many factors in eukaryotes assist with initiation?
RNA polymerase I
5,8 S, 18 S and 28 S rRNA genes
RNA polymerase II
all protein-coding genes, plus snoRNA genes, miRNA genes, siRNA genes, IncRNA genes, and most snRNA genes
RNA polymerase III
tRNA genes, 5S rRNA genes, some snRNA genes, and genes for other small RNAs
transcriptional activators
what helps RNA polymerase II by binding to specific sequences called enhancers
enhancer
What helps attract RNA polymerase?
general transcription factor
what helps position RNA polymerase at promoter?
25 nucleotides
when can the tata box during transcription?
transcription initiation complex
RNA polymerase and other transcription factors
double stranded DNA
what does the RNA polymerase need to gain access to after the Transcription Initiation Complex is formed?
TF II H
what acts ad helicase and undwinds the DNA to expose the template strand?
Cterminal domaij
when does phosphorylation of RNA polymerase occur?
RNA processing
what occurs in tandem with elongation?
CTD phosphorylation
what is it when there are covalend modifications to the ends
RNA splicing
what is it when there are removal of introns in RNA?
capping 5' end with guanine
poly-A tail on 3' end -only exons
what is needed to go from pre-mRNA to mRNA?
TFIID
recognizes TATA box
recognizes other DNA sequences near the transcription start point
TFIIB
recognized BRE element in promoters; accurately positions RNA polymerases at the start site of transcription