MCB Block 3 Flashcards
1
Q
What are liposome used for?
A
Drug delivery
2
Q
What do GPI do?
A
Attach protein to the PM.
Found at lipid rafts
3
Q
RBC Transmembrane proteins
A
Band 3 and Glycophorin
4
Q
RBC Linking Proteins
A
Protein 4.1 and Ankyrin
5
Q
What is specrtin and where is it found?
A
Alpha/beta F-Actin. Linked to junctional complex within RBC
6
Q
Function of Nucleolus?
A
rRNA synthesis and Ribosome assembly
7
Q
What are nucleoporins made up of?
A
Glycoproteins of NPC
8
Q
What is inner membrane of nuclues supported by
A
Lamin intermediate Filaments. Maintains cell shape and protects membrane.
9
Q
What is the sig. seq. to go into the nucleus.
A
NLS
10
Q
What is the sig. seq to leave the nucleus
A
NES
11
Q
What G protein family is used for transport in and out of the nucleus?
A
RAN GTPase
GEF- GDP to GTP
GAP - GTP to GDP
12
Q
What do Lamin A, B, and C form during phosphorylation of CDK1
A
Lamin B: Gene, anchored to inner membrane
Lamin A/C: Splice variants, forms free heterodimers
13
Q
What are the Cajal bodies and Gems? (subnuclear structure)
A
Maturation of snoRNA and snRNA
Contain the survival of motor neurons protein (SMN)
14
Q
Substructures of the nucleolus
A
Fibrillar center
Dense fib component/ PARS FIBROSA
Granular component/ PARS GRANULOSA
15
Q
Fibrillar center
A
Transcriptionally INACTIVE DNA
16
Q
Pars Fibrosa
A
rRNA being transcribed, then modified by snoRNPS
17
Q
Pars Gransulosa
A
rRNAs being assembly with ribosomal proteins
18
Q
Function of the smooth er
A
Steroid hormone synthesis, detox, membrane lipid synthesis
19
Q
Function of the rough er
A
Lipid and protein production, modification and intracell trafficing
20
Q
If there is no ER signal, where will the protein end up?
A
It will be made by a free ribosome and be discharged in the cytosol post translationally
21
Q
Which amino acids are N-linked glycosylated?
A
Asparagine
22
Q
Which amino acids are O-linked glycosylated?
A
Ser/Thr
23
Q
What GTPase are used for vesicle formation?
A
ARF/SAR GTP
ARF= COP 1
SAR = COP 2
24
Q
ARF/SAR GEF vs GAP
A
GEF: Promotes coat protein assembly. GDP to GTP
GAP: Promotes coat disassembly. GTP to GDP
25
Function of Golgi app?
Major site of carbohydrate synthesis (GAGs)
Addition of oligosac to proteins and lipids.
Acquire specificity
26
Regulated exocytosis
Vesicles wait for external signals, usually an increase int he cytosolic calcium
27
Transcytosis
Endo + exocytosis across epithelium.
| pH Determines direction (usually from low to high)
28
Which GTPase is used in vesicle fusion?
```
RAB, GTP and GDP
RAB GTP (on the vesicle)
Rab effector = tethering protein, on the target membrane
```
29
V-Snare, T-Snare, and extra protein used in nuerons?
SynaptobreVin
SynTaxin
Synaptotagmins (Ca2+sensor) (interacts with T-Snare)
30
What is the final stage of vesicle fusion? What protein is involved?
allowing membrane fusion
NSF assist in dissociation
of synaptobrevin from syntaxin, allowing membrane fusion
31
2 coats used for receptor mediated endocytosis?
Clatherin (for lysosome) and Caveolin coats
32
What proteins are needed for receptor mediated endosytosis?
Adaptins to bind to the receptor, which allows Clatherin coat to form then Dynamin helps the vesicle pinch off.
33
What are opsonins?
Opsonins are anything that is engulfed by a phagosome
34
Caveolin coat
Form from lipid rafts
Invaginations in PM
Coat of calveolin protein (integral membrane protein)
Have SPIKES on COAT
35
What is the tag called for lysosomes?
M6P. Tagged at the Cis-golgi by GlcNAC Phosphotransferase
| M6p receptor is in TRANS golgi
36
Early Endosome + Primary Lysosome = ...
Late enosome
37
Late Endosome + Maturation = ....
Secondary Lysosome
38
Endosome + Lysosome --> Endolyosome + Maturation = .....
Secondary lysosome
39
What type of pump is found on lysosome?
V-Type ATPase: Pumps H+ into lysosome.
40
Autophagy
Break down of old or unneeded proteins
41
Multivesicular Bodies
Maturation of early endosomes containing endocytic vesicles to late endosomes occurs.
MVBs shed vesicles to recycle material back to PM
Proteins destined for MVB receive mono-ubiquitin tag (down regulation of receptors
42
If lysosome can't degrade material, what happens to that material?
Residual body that can be exocytosed or remains as lipofuscin (pigmented lipids)
43
Peroxisomes function
Carry out Oxidative Reactions that generate H2O2 for oxidative purposes.
Catalase destroys the H2O2 to detoxify the cell.
44
Peroxin tag?
SKL. (Ser-Lys-Leu)
| Peroxisome are made on free ribosome in cytosol
45
3 peroxisome synthesises
Plasmalogen (Myline;schwann)
Bile acid
Lipid Biosynthesis
46
3 peroxisome degradations
VLCFA Beta oxidation
Purine Catabolism (degrade Uric acid using Xanthine Oxidase)
H202
47
Oxidase of peroxisome
Synthesis H2O2
48
Catalases of peroxisome
Eliminate the H2O2 into H2o and O2
49
What do peroxisomes contain within? What gene encodes them?
Peroxisomal enzymes aka Peroxins. Encoded by PEX.
50
What do peroxins form?
Channels within membrane
51
Where is the only place VLCFA degradation can occur?
In peroxisomes. Broken down until get down to 10 carbons.. Then can move to mitochondria to be transformed into Acetyl CoA.
52
Where is cardiolipin found
On the inner membrane of the mitochondria and it is thought to contribute to the impermeability of the membrane
53
Where is cardiolipin synthesized? Structure?
Outer mito membrane
| 4 FA Tails
54
Where does Glycolysis, TCA cycle, and ETC occur?
```
Gly= cytoplasm
TCA= Mito matrix
ETC= matrix ( even though the ETC is on the inner membrane itself)
```
55
Where can you find brown adipose? What do you find in there?
In mitochondria.
| Find uncoupling proteins Thermogenin on the inner membrane.
56
Thermogenin
A channel on the inner membrane of the mitochondria that allows protons to "leak" from cytoplasm to matrix. DOESNT use ATP SYNTHASE.
Instead releases energy as HEAT
57
Reactive Oxygen Species
Produced during oxidative phosphorylation. Can inactivate electron acceptors and damage RNA, DNA.
58
2 proteins that work against generation of superoxides (ROS)
GPX and SOD2. THey convert the ROS into water
| glu peroxidase, and superoxide dismutase
59
Apoptosis Enzymes
Bax, Bad, BCL-2
60
BAD enzyme
Dimerizes with BCL-2 and prevents BCL2 from dimerizing with BAX
61
BAX Enzyme
Forms pores on outermembrane of mito
62
BCL-2 Enzyme
Anti-apoptotic. Dimerizes with Bax and prevents it from forming a pore.
63
Intrinsic pathway for cell death
p53 will get activated and it will go on to activate Bax --> make pores in the outer membrane of mitochondria --> cytochrome c form a complex (apoptosome) that will activate capsases 9 --> activate caspase 3/7 --> Apoptosis
64
Extrinsic pathway for cell death
Death ligand bind to death receptor outside the mitochondria
Activate procaspase 8 --> caspase 8 --> activates caspase 3/7 --> apoptosis
65
Protein import into the mito
Protein has Mito sig. seq. Binds to HSP70+ in the cytosol to prevent folding of protein.
TOM and TIM recognize sig. seq.
HSP70+ binds to TOM
HSP70+ binds to TIM (but tim needs an electrochemical gradient)
HSP70 brings in the protein (function like Bip)
Matrix Protease removes Mitochondrial Signal Sequence
HSP60 + ATP can help the protein fold inside of the matrix if it does not fold spontaneously.
66
TOM and TIM of Mito
Tom: Translocase of Outer Membrane
Tim: Translocase of Inner Membrane
67
HSP 60+ of mito
can help the protein fold inside of the matrix if it does not fold spontaneously.
68
Mito GENOME H and L Loop
H loop is all coding execpt for D-Loop.
(12 mRNA)
L codes for 1 mrna and several tRNA
69
How many genes does Mito genome make
33 genes all together
13 protein coding genes
22 tRNA
2 rRNA
70
DNA Poly and helicase in mito
Gamma and Twinkle
71
DNA Poly Gamma and the alpha subunit
encoded by nuclear DNA.
| PLOG encodes for alpha subunit of the gamma.
72
HIV Patients treated with AZT
DNA polymerase δ is not inhibited because the nucleotide entry channel in this polymerase does not accept the AZT derivative, so nuclear DNA replication is not affected
DNA polymerase γ is inhibited by the AZT derivative causing depletion of mitochondrial DNA, explaining the myopathy as a side effect of AZT therapy
73
AZT
AZT is a drug that stops Reverse Transcription from occurring in the HIV Virus.
74
Processesing of mito MRNA
Polyadenylated by not capped
75
Mito Trnx
2 promoters in control region (D-loop) HSP/LSP. Transcribed at same rate.
RNA endonuclease cuts into tRNA,rRNA, mRNA.
NO INTRONS
Recomb not evident
76
Mito TrnsL
Starts with N-Formyl Methionine
| 22 tRNA in mito translation
77
Why does the accumulation of mito occur faster compared to nuclear DNA
occurs 10 fold faster because of the formation of oxidative radicles
78
3 types of mutations in Mito
| What do they affect?
1) Deletion/dup
2) point mutation in tRNA (prot. syn)
3) Missense mutation in coding region that impairs ox. phos.
Directly or indirectly effect oxid phos and atp production.
Cause lactic acidosis and ragged red muscle fibers (cause more mito to form b/c think theres energy deficiency)
79
How can you detect giant deletions in mitochondrial genome
Use Southern blot or PCR.
| Alway find in heteroplasmic state
80
Two types of intracellular signaling proteins
Kinases (tyrosine kinases, serine/threonine kinases)
GTP-bindng proteins (G-proteins)
81
2 signaling pathways of GPCR
1) cAMP as 2nd messenger
Effector: Adenyl cyclase
uses Gi and Gs
2) DAG and IP3 as 2nd messenger
Effector: PLC
Uses Gq
82
Adenyl Cylcase Path
Adynl activated --> Converts ATP to cAMP --> Activates PKA by bing to its regulatory proteins --> The catyltic PKA enters nucleus --> Bind to CREB --> Bind to CRE --> Gene regulation
PKA = Adenyl Cyclase
83
PLC Path
PLC activated --> breaks down inositol phospholipid into IP3 and DAG --> IP3 opens calcium channel on endo reticulum --> Ca binds to DAG to activate PKC Ser/Thr
PKC = PLC
84
Tyrosin Kinase Receptor pathways
PLC and PI3K and GRB2
85
PI3K Pathway
RTK phos PI3 Kinase --> phos PIP2 --> Phos PIP3 activate PKB/AKT --> AKT phos BAD by freeing the apoptosis inhibitory protein leading to the inhibition of apoptosis
86
Cell survival inhibitions
PKB inhibits BAD
BAD inhibits BCL-2 by heterodimerizing with it.
BCL-2 inhibits BAX
BAX forms pores... Active Bad = active Bax
87
Ras-MAPK Path
GRB2 SH2 domain binds to phos Thyrosin on activated RTK.
SH3 domain of GRB2 attracts RAS-GEF SOS. This activate Ras protein with GTP.
Ras --> Raf --> Mek --> Erk (MAPK)
88
Cytokine Path JAK/STAT
| No TK activity
No enzymatic activity.
2 monomer receptors come close --> JAK tyrosine phos each other --> Phos binding site -->STAT binds to site --> Phos STAT --> Dimerize STAT --> Enter nucleus
89
What element is essential for DNA binding
ZN2+. Receptors bind to these
90
Microtubule energy
GTP and GDP. Growth on + end.
| Hydrolyze the beta tubule
91
Where does catastrophe occur and dynamic instability occur?
Microtubules. If hydrolysis catches up with dimer addition
92
Singlets, doublets, triplets
1: carrying, chromosomes
2: Cillia/flagella/Axoneme
3: MTOC (Centriole and Basal bodies)
93
Axoneme structure
made up using 9 microtubules doublets and 2 singlets in middle
94
Centriole structure
9 MT triples
95
Centrosome
2 centrioles
96
Gamma tubulin
Associated with centrosome through the pericentriolar.
| Where singlet MT extend through from MTOC
97
MAPS
Protect from MT disassembly. Example TAU. Inhibit tubulin dissociation.
Make MT more stable which causes less catastrophes and makes them less dynamic
98
Kinetichore
Shorten as the cell goes from Metaphase to Anaphase.
Dynein pulls the Chromatids in towards the centrosome
99
Polar
Grow as the cell goes from Metaphase to Anaphase
Kinesin: walks towards the + end, pushing the centrosomes apart
100
Basal body =
MTOC ; 9 triplets
| 2/3 MTs from each Triplet form Doublets that protrude into the Axoneme for cilia
101
Actin Cross linking proteins
Parallel bundles = A-Actinin
Fimbrin, & Vilin
Webs/gels= Spectrin and filamin
102
A Actinin
Loost packing, STRESS FIEBRS, contractile, cytokenesis
103
Fimbrin
Tight packing of bundles, MICROVILLI, LAMMELPODIA, non-contractile
104
Fimbrin and Villin
Crosslink acting to increase SA for absorption.
| Non-contractile
105
Where do you find stereocilia
Mechanoreceptors of hair cells in the inner ear
Epididymis absorptions
106
Filamin
3D crosslink of actin under the Plasma Membrane for support
107
Spectrin
Actin cross link protein in RBC
108
Dystrophon
Anchors actin cytoskel to the sarcolemma in skeletal muscles
109
Vinculin & Talin
Attach actin cytoskel to membranes in focal adhesions
110
Cadherins
Cell to cell contacts mediated by this protein
111
3 types of cytoplasmic IF
Keratin (Epithelia), Neurofilaments(Nerve cells), vimentin (CT, Muscle, neuroglial cells)
112
Nuclear Lamins
Nuclear filament found in all animal cells
113
Keratin IF Defects
Epidermolysis Bullosa simplex, Hyperkeratosis, Plantopalmar keratoderm
114
Epidermolysis Bullosa Simplex
Auto Dom Defect in Basal layer
Keratin 5,14.
Rupture cells in epidermis basal layer
Wearing shoes causes blisters above basement membrane. Fragile skin
115
Epidermolytic Hyperkeratosis
Keratin 1, 10 Defect in suprabasal layer
Excess proliferation
Prone to infection
Hyperproliferation, Thickened skin, chronic wounding
116
Epidermolytic Plantopalmar Keratoderma
Keratin 9 defect in cornified layer
palms of hand and soles of feet
Everything above basal layer is ripped off
117
Desmin
IF that lines up the myofibrils so they're packed together for their strength
118
Lamins
Lines inner surface of Nuclear envelope
| Structural stability of nucleus, protects the DNA
