Cytoskeletan

Question 1

• Microtubules, microfilaments, intermediate filaments: Structure? Predominant protein? Function? Accessory protein? Role of nu-?

Answer 1

1. ) Microtubules: Tubular, 25 nm; tubulin a,B; movement flagella/cilia scaffolding, move organelles including chromosomes; motor proteins dyenins/kinesins, assembly dissassembly; GTP
2. ) MF: helical, 5-9 nm; actin; cell movement/contraction; motor proteins, myosins, cross linking, brancing, anchor; ATP
3. ) Intermediate Filaments: Complex rope (10nm); keratin, vimetin; mechanical stability; assembly/dissassembly; cross linking; membrane anchor

Question 2

• Microtubules: Structure? Growing end? What regulates growing? Breaking down? Ex? (2) Related disease? Mother/daughter where tubulin grows from? Motor proteins? ATP leads to? MT very important in what cells? Diseases related? 4 parts/MT of cell division?

Intermediate Filaments: Structure? Often 8 tertramers twist to make? Where do you find keratins? vimentin? neurofilaments? lamins? keratin 8 mutation bad where? Lamin mutations can lead to? Ex?

Answer 2

• Heterodimer; +; GTP caps; severing katenin family; spastin, fidgetin; Hereditarty Spastic Paraplegia; Centrioles/Centrosomes; Kinesin, dyenins; kinesin head attaching; Axons; neurapathies; 2 centrosomes go to different ends, Astral MT hit walls, Kinetophore MT hit chromosome, overlap MT overlap + ends
• Varies; rope; cytoplasm epithelia; cytoplasm CT neuroglial; cytoplasm nerve cells; nucleus of animal cells; lover; mutation of nuclear envelope; CMT

Question 3

• Microfilaments: 2 key growing processes? What forms in the presence of ATP? Then two helical strands of this make? How many proteins play role in this? Capping protein? Severing protein?
• Role of actin in polarity of epithelial? AJ made by what 2 proteins? Loss of adhesion leads to? How are microvilli made? Mutations lead to?
• For movement, actin binds to what protein family? Similar to? Which is related to striated muscle? In moving organelles? Striated muscle contraction steps? (3)

Answer 3

• nucleation & extension/retraction; g actin; F actin; more than 60; gelsolin; cofillin
• Anchoring protein for tight and adherens junctions; cadherins and catenins; EMT cancer formation; crosslinking villin and fimnrin; microvillin inclusion disease
• Myosin; kinesin; Mysoin II; Myosin I and V; ATP causes dissosiation; p leaving causes attachment; ADP leaving causes power stroke

Question 4

• Amoeboid locomotion steps? (4)
• Related diseases: Lissencephaly? Metastasis?
• Actomyosin ring? Drives what? Tightly regulated for?
• Assymmetrical cell division activated what 2 ways? RBC’s created how? Platelets created how? Spermatogonia made how?

Answer 4

• protrusion; attachment of protrusion; traction to pull forward; detachment
• absent gyri in brain due to minimal neuronal migration via mutated n-cofilin; spread of cancers
• Present in cytokinesis of cell division; cleavage of daughter cells; cell symmetry
• Rho-Formin and Rho-Rock kinase; enucleation; abortive cytokinesis; incomplete cytokinesis