Cytoskeleton Flashcards
Why does the cell need a cytoskeleton? [2 marks]
- To keep its shape
- To move organelles
- Tomove the cell
What does actin do? [3 marks]
- Cell migration
- Cell shape
- Intracellular transport (via integrins)
Actin structure [5 marks]
- Thin
- Flexible (either 2D network or 3D gels)
- Helical F actin chain made up of G actin
- Polar
- Associates with actin binding proteins
Isoforms of G actin [3 marks]
- Alpha (muscle)
- Beta (non muscle)
- Gamma (non muscle)
What is profilin? [2 marks]
- Actin binding protein
- Facilitates actin polymerisation
What is thymosin b4 [2 marks]
- Actin binding protein
- Prevents addition of actin to F actin
What are actin bundling proteins? [2 marks]
- Actin binding protein
- Keeps F actin in parallel filaments
What are cross linking proteins? [2 marks]
- Actin binding protein
- Maintains F actin in a gel like meshwork
What other more well known actin binding proteins are there [2 marks]
- Motor proteins
- F actin severing proteins
What do intermediate filaments do? [2 marks]
Provide mechanical support via 3D frameworks
- TThey are the toughest filaments)
What is the structure of intermediate filaments? [2 marks]
- Ropelike formation of tetramers
- Unit with N head, C tail and central rod like domain
Intermediate filament units [4 marks]
CYTOPLASMIC: Keratin Vimentin Neurofilaments NUCLEAR: lamins
What is fillagrin? [2 marks]
- Intermediate filament binding protein
- Binds keratin filaments into bundles
What is synamin and plectin? [2 marks]
- intermediate filament binding proteins
- binds vimentin and desmin
What are desomosomes? [2 marks]
- Places where IFs join up to cell-cell junctions
- To provide strength
