Gräf Flashcards by Anni Saß

Actin SU binding protein: thymosin

binding SU, prevent assembly

How well did you know this?

Not at all

Perfectly

Actin SU binding protein: fromin

nucleates assembly, binds + end and stays associated

How well did you know this?

Not at all

Perfectly

Actin SU binding protein: ARP complex

nucleates assembly to from a web and stays associated with the - end

How well did you know this?

Not at all

Perfectly

Actin SU binding protein: profilin

binding SU and speeds elongation

How well did you know this?

Not at all

Perfectly

Actin filament binding protein: cofilin

binds ADP actin filamentes at - ends, speeds dissassembly (accerlates)

How well did you know this?

Not at all

Perfectly

Actin filament binding protein: gelsolin

serves filaments and binds to + end

How well did you know this?

Not at all

Perfectly

Actin filament binding protein: filament bundling, crosslinking and attachement to the membranes

fimbrin
filaminin
alpha - actinin
spectrin
ERM

How well did you know this?

Not at all

Perfectly

Actin filament binding protein: capping protein

prevents assembly and disassembly at the + end

How well did you know this?

Not at all

Perfectly

Actin filament binding protein: topomyosin

stabilizes filament

How well did you know this?

Not at all

Perfectly

Actin-binding proteins… doing what?

regulate nucleation, assembly, disassembly
build or sever supramolecular structures (bundles/networks)
determine stability, elasticity and rigidity of cells

How well did you know this?

Not at all

Perfectly

Dynamic instability in micro tubuli

assembly, catastrophe, disassembly,rescue

How well did you know this?

Not at all

Perfectly

Functions of alpha beta dimer microtubule-associated proteins: strathmin

binds su, prevents disassembly

How well did you know this?

Not at all

Perfectly

Functions of alpha beta dimer microtubule-associated proteins: gamma TuRC

nucleus assembly and remains associated with the - end

How well did you know this?

Not at all

Perfectly

Functions of alpha beta dimer microtubule-associated proteins: +TIPs

remains associated with the + end (growing) and can link them to other structures as membranes

How well did you know this?

Not at all

Perfectly

Functions of microtubule-associated proteins (microtubule): kinesin13

enhances catastrophic disassembly at the + end

How well did you know this?

Not at all

Perfectly

Functions of microtubule-associated proteins (microtubule): katanin

serves microtubules

How well did you know this?

Not at all

Perfectly

Functions of microtubule-associated proteins (microtubule): filament binding and crosslinking

TAU, MAP2, Plectin

Functions of microtubule-associated proteins (microtubule): MAPs

stabilizin tubutles by binding the sides

Functions of microtubule-associated proteins (microtubule): XMAP2015

stabiliting + ends and accerlerates assembly

Microtubule specific drug: Taxol

binds and stabilizes microtubuls

Drugs: which does binding the SU and prevent the polymerization?

Nocodazole
Vinblastine, vincristine
Colchicine, Colcemid

Centrosome: MTOC

• Non-membranous organelle
• Largest protein complex of a cell with more than 100 different proteins
• Main microtubule-organizing center of the cell
• Director of cell architecture
• Evolutionarily ancient: roots back to the last eukaryotic common ancestor.
Present in most eukaryotes; secondary loss in higher plants.

Nuclear composition

Double membrane, outer membrane connected to the ER
Nuclear pores are large proteins complexes allowing passage of large molecules through the
nuclear envelope.
The nuclear lamina beneath the inner membrane consists of lamins (= IF proteins)
Chromatin with DNA
Nucleolus (site of ribosome biogenesis)

Chromosome

DNA molecule(s) + associated proteins; prior to S-phase 1 molecule, after S-phase 2 DNA molecules

Chromatid

1 DNA molecule + associated proteins

Chromatin

total nuclear DNA together with packaging proteins

Euchromatin

transcriptionally active, almost uncondensed chromatin (genes)

Heterochromatin

transcriptionally inactive, condensed chromatin

Centromer

connecting site of sister chromatids consisting of condensed DNA with specific associated proteins

Kinetochore

centromeric substructure maturating only during | mitosis (before prekinetochore). Defines the attachment site for spindle microtubules

Centrosome

microtubule-organizing center, nucleation and binding site for spindle microtubules.

Telomere

specialized structure at each chromosome end that protects ends and ensures complete replication of chromosome ends during S-phase

Major function: nuclear import and export 8-fold symmetry

* Pore size 30-40 nm * Passive diffusion of metabolites and globular proteins up to 60 kD (also depends on shape and protein species) • Disassembly into soluble subcomplexes during mitosis; re-assembly starts in telophase * up to 1000 molecules per sec * Export: RNPs, ribosome subunits, tRNAs, mRNAs * Import: transcription factors, chromatin components, ribosome proteins, nuclear lamina components... * Molecules may pass NPCs in both directions simultaneously. * directional transport requires NLS (z.B. PKKKRKV) or NES. Retention inside the nucleus requires NRS

Cyclins

* cyclic, cell cycle- dependent concentration * Regulation by ubiquitylation and proteasomal degradation * 2 important E3- enzymes: APC/C (acting with two different substrate binding factors Cdc20 and Cdh1) and SCF (= Skp1, Cullin, F-Box)

cell cycle control by CDKs: 3 different | main CDKs

Cdk4/6-CyclinD =G1-Phase CDK Cdk2-CyclinE/A = S-Phase CDK Cdk1-CyclinB =M-Phase-CDK

3 important ubiquitin ligases

* APC/CCdc20 * APC/CCdh1 * SCF

Prophase

1. Chromosome condensation (condensin translocates into the nucleus) 2. Begin of histone H3 phosphorylation 3. Decomposition of the nucleolus 4. Halt of transcription 5. Centrosome separation with 2 separate microtubule asters 6. Disassembly of most intermediate filaments (cells round up) 7. fragmentation of Golgi apparatus and ER 8. reduced exocytosis > internalization of membrane anchors and receptors

kinesin 13

MCAK

kinesin 4

CENP-E

Cytokinese

* Formation of a contractile actin/myosin-ring in the equatorial region * Midbody formation (protein complex in the region of interdigitation of pole-to-pole MTs) with a role in signal transduction * Transport of membrane vesicles to the cleavage furrow * Translocation of regulatory chromosomal passenger proteins to the cleavage furrow * Constriction of the actomyosin rings starting in anaphase B * Final abscission at the site of constriction by mass vesicle fusion employing a v/t- SNARE mechanism, centrosomal components and the ESCRT complex