Important Proteins Flashcards
(97 cards)
1
Q
Glycosaminoglycans (GAGs)
A
Link to core proteins in the interstitial ECM to form proteoglycans
2
Q
Glycoproteins
A
Fibrous proteins in the interstitial ECM
3
Q
Collagen
A
A protein that provides tensile strength in connective tissues (bone, skin, hair, nails)
4
Q
Collagen
A
A protein that provides tensile strength in connective tissues (bone, skin, hair, nails)
Triple helix
5
Q
Pre procollagen
A
The cytoplasmic form of collagen
6
Q
N proteinase
A
Cleaves the N terminus of procollagen extracellulary
Confers ability to assembly into collagen fibres
7
Q
C proteinase
A
Cleaves the C terminus of procollagen extracellularly
Confers ability to assembly into collagen fibres
8
Q
Proteoglycans
A
Extracellular proteins linked to glycosaminoglycans in the interstitial ECM
9
Q
Collagen type4
A
Forms the basal lamina with laminin
10
Q
Laminin
A
Forms the basal lamina with collagen type 4
11
Q
Laminin
A
Forms the basal lamina with collagen type 4
Organises the sheet
Triple helix with a cross
12
Q
Nidogen and perlecan
A
Hold the basal lamina together
13
Q
Collagen type4
A
Forms the basal lamina with laminin
GlyXY repeats confer bendiness
14
Q
Laminin
A
Forms the basal lamina with collagen type 4 Organises the sheet Triple helix with a cross 15 isoforms Self assembles
15
Q
Nidogen and perlecan
A
Hold the basal lamina together
Laminin and collagen 4 sheets cross linkage
16
Q
Integrins
A
Transmembrane receptors that couple the matrix to the cytoskeleton
17
Q
Talin and vinculin
A
Actin binding proteins ABPs
18
Q
N-CAM
A
Adhesion molecule in neural crest cells
19
Q
Laminin and fibronectin
A
Cause neural crest cells to migrate
20
Q
Tether proteins
A
Aid membrane fusion
21
Q
Exchange factors
A
Involved in cell signalling
22
Q
Sorting signals
A
Amino acid labels that tell a protein where to be transported
23
Q
Signal peptidases
A
Remove the sorting signals after transport
24
Q
Nuclear pore proteins
A
30 proteins make a ‘basket’
Only 5 types of proteins:
- Annular subunits (central)
- Lumenal subunits (TM)
- Ring subunits (faces)
- Fibrils (FG repeats)
- Nuclear basket
25
Transcription Factors
Proteins which activate gene expression and bind to specific promotor regions
26
Nuclear localisation signals
Positively charged residues that tell a protein to go into the nucleus
27
Karyopherins, Importins
Nuclear localisation signals
28
Nuclear import adaptor proteins
Receptor is binding another protein (an adaptor) that bind the protein
29
Ran
Small GTPase - molecular switch with two states, active (GTP cound) inactive (GDP bound)
30
GAPs
GTPase activating proteins
Switch Ran OFF
By increasing rate of GTP hydrolysis
31
GEFs
Guanine nucleotide exchange factors
Turn Ran ON
By increasing rate of GDP-GTP exchange
32
Chaperones
Are proteins that bind and block polypeptide folding
33
Hsp70
Chaperone protein family in mitochondria
34
TOM
Translocator outer mitochondrial membrane complex
35
TIM
Translocator inner mitochondrial membrane complex
36
Pex 5 and Pex 7
Involved in Peroxisome biogenesis
37
Catalase
Enzyme in peroxisomes Degrades H202 produced by Oxidases
38
Oxidase
Produces H202 in peroxisomes
39
26S proteosome
Degrades Pex5
40
Pex1 and 6
Form the lever arm for transient pore model
| ATPases
41
SRP
Signal recognition particle
Made out of RNA and 6 proteins Hydrophobic pocket lined with methionines recognises N terminus signal sequence
Has a translational pause domain (like a finger that stops the ribosome translating) Brings the ribosome to the ER SRP binds to SRP receptor in the ER membrane
42
Sec61
Protein translocator in the ER Hetero trimeric complex
Bundled alpha helices with a central pore Pore is usually closed by a small a-helix 'plug' Signal peptide displaces the plug allowing transport of the protein
43
NO synthase
Makes nitric oxide
| Is used as a signal to relax smooth muscle in blood vessels
44
Connexins
6 subunit protein that forms GAP junctions (small channels in cell membranes)
Twist open or closed
45
G protein coupled (GPCRs)
Receptors have 7 transmembrane domains (serpentine)
Ligand binds, complexes with trimeric G proteins (alpha beta gamma subunits)
Activate an enzyme at the plasma membrane
Transmits a signal
e.g generation of cAMP by adenylyl cyclase
46
Receptor Tyrosine Kinases
Form dimers in the membrane
Activates phosphorylation domains in the cytosol
Beginning of signal transduction cascade
47
Phosphatases
Enzymes that dephosphorylate (kinase antagonists)
48
Adenylyl cyclase
Membrane bound enzyme Produces cAMP from ATP
| Activated by G proteins
49
Phosphodiesterases
Enzyme that converts cAMP to AMP
50
Protein Kinase A (PKA)
Phosphorylates Two kinds of target proteins: Fast (phosphodiesterase switch) Slow (CREB (dna transcription))
51
AKAPs
A kinase anchoring proteins A group of proteins which bind the regulatory subunit of protein kinase A (PKA) and confine the holoenzyme to discrete locations within the cell
52
Calmodulin
Protein which changes conformation allosterically when bound to Ca2+ Needs 2 Ca2+ to bind Targets CAM kinases
Hb also does this allosteric change
53
CAM kinases
Autophosphorylate So even when Ca2+ is lost, the signal is active until phosphatases overwhelm it
54
mTOR
Cytoplasmic Kinase
| Phosphorylates Ser/Thr residues
55
RHEB
Ras family small GTPase
56
TSCs
Tuberous Sclerosis Complex
57
AKT/Protein kinase B (PKB)
A serine/threonine-specific protein kinase that plays a key role in multiple cellular processes such as glucose metabolism, apoptosis, cell proliferation, transcription and cell migration
58
mTORC1
Promotes protein synthesis
Promotes ribosome production
Inhibits protein degradation
mTOR pathway
59
mTORC2
Changes actin cytoskeleton and cell shape
mTOR pathway
60
elF4E
Translation initiation factor
| Indirectly activated by mTOR by inhibiting an inhibitor of elF4E
61
S6 kinase
Phosphorylates ribosomal protein S6
Increases translation of ribosomal components
mTOR pathway
62
Cdc42
Rho family GTPase
Central regulator of cell polarity
Recruits many proteins involved in actin, MTs, trafficking and cell junctions
63
Caspases
Protease enzymes in apoptosis
64
TNF
Tumour necrosis factor
Cell signaling protein (cytokine) involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction
Produced chiefly by activated macrophages, although it can be produced by many other cell types such as CD4+ lymphocytes, NK cells, neutrophils, mast cells, eosinophils, and neurons
65
Fas
The Fas receptor is a death receptor on the surface of cells that leads to programmed cell death (apoptosis)
66
FADD, TRADD
Fass associated death domain protein
| TNF type 1 death domain protein
67
Bcl proteins
B cell lymphoma 2
| Involved in intrinsic apoptosis, either pro or anti apoptotic
68
BH123
Pro apoptotic Bcl protein on mitochondrial membrane
69
Bcl 2
Anti apoptotic Bcl protein, inhibits BH123
70
BH3 proteins
Pro apoptotic protein that binds Bcl2
71
Apaf1
Apoptotic protease activating factor
| in mitochondria
72
Apoptosome
Oligomer of 7 Apaf1 proteins with bound Cyt c
| Plus a central procaspase9
73
IAPs
Inhibitors of apoptosis
| BIR domain binds caspases
74
Anti IAPs
Block IAPs
| Mitochondria
75
Jnk
Stress activated MAP kinase
| Causes transcription of BIM and this apoptosis
76
Bid, Bim and Puma
Potent activators of apoptosis
| Inhibit all Bcl2 family
77
Formin
Nucleates straight actin (bundled), remains at plus end
78
ARP2/3 complex
Nucleates branched actin (lamellipodia), remains at minus end
79
Profilin
Pro- actin formation, binds subunits and speeds up
80
Thymosin
Binds subunits and prevents actin formation
81
Cofilin
Binds actin at the minus end, speeds up disassembly
82
Gelsolin
Severs actin filaments and binds to plus end
83
Capping protein
Prevents assembly and disassembly at actin plus end
84
Tropomyosin
Stabilizes actin filament
85
Fimbrin, alpha actinin, filamin, spectrin,ERM
Proteins that bundle, cross link and attach actin to the membranes
86
Par proteins
Kinases
Cause asymmetric positioning of the mitotic spindle
Polarise the cell
87
Scribble and Crumbs
Organise polarity of cells to the basal lamina with Par proteins
88
Lkb1
Human gut par protein, mutations cause polyps
89
Centrosome
Nucleates microtubules
90
Centriole
MT organising centre
mother and daughter
same structure as the basal body
91
Spindle pole body
Centriole equivalent in yeast
92
Nexin
Connects double MT in outer ring of flagella
| Important in flagella wave form - causes MT to bend
93
Centrin
Structural protein found in the basal body
| Controls basal body number (mutants have too many, vfl mutant)
94
PitX2
Transcription factor positioned by ciliary beating during embryogenesis
95
Gene regulatory proteins
Bind directly or indirectly to the regulatory DNA adjacent to the genes that are to be controlled
96
Protists are far more diverse than
multicellular animals, plants and fungi
anatomy is elaborate with sensory bristles, beating cilia, mouth parts and contractile bundles
Allow distant evolutionary past to be put in context by genome analysis
97
Saccharomyces cerevisiae is a good model organism because
It has a very small eukaryotic genome
robust and easy to grow, grows rapidly
can divide asexually or sexually, and can be induced
good for studying cell cycle - highly conserved
