Flashcards
DG - Lecture 10
Cards in this deck (48)
- 1kinesinMT + end motor protein
Many types (> 14 known classes)
Heavy chains
ATPase activity and bind MTs
Light chains recognize cargo
Anterograde movement
ATP hydrolysis causes conformational changes which results in movement - 2dyneinMT - end motor protein
ATPase activity
Interacts with another accessory protein, Dynactin, which binds to cargo
Retrograde movement
ATP hydrolysis causes conformational changes which results in movement - 3which organelles can undergo both enterograde and retrograde motion?endosomes and mitochondria
- 4how does actin polymerizemonomeric globular actin (G-actin) turns into filamentous (F-actin) by growing at both + and - ends (although + is faster)
- 5profilinencourages actin polymerization
- 6cofilinencourages actin depolymerization
- 73 structures of actin1. bundles 2. networks 3. support structures
- 8actin organization - actin binding proteins found (ie fimbrin)
- 9actin bundles found (fimbrin, alpha actinin etc)microvilli, folopodia, focal adhesions
- 10alpha actinin found
- 11spectrin (actin network protein)
- 12actin networks foundinner PM, leading edge of migrating cells
- 13filamin (actin network) found
- 14actin support structures foundplasma membrane for actin linking
- 15dystrophin (for support structure) found
- 16significance of RBC and spectrinRBC has a lot of spectrin, which is found at the cell cortex (outer), allowing for the unique shape - biconcave disk -> spectrin helps pull the PM in
- 173 places that actin can accumulate in a structural/epithelial
- 184 places actin can accumulate in a moving/mesenchymal cell+ stress fibers
- 19role of actin in mitosisform contractile ring during cytokinesis
- 20branched actin formationa mesh/lattice that is accomplished (nucleation and branching)nthrough the help of Arp2/3 complex
branching is stimulated by adding laterally to an existing actin
+ end grows and Arp2/3 situated at - end - 21fn of branched actinfound at the leading edge of cells to push the membrane forward
- 223 classes of myosin1,2, 5
*myosin always moves toward + end
has heavy and light chains, ATPase activity and requires Ca2+ - 23myosin 2the most abundant
- 24myosin 5transport fn
- 25myosin 1membrane assoc and endocytosis fn (think macrophages)
- 26does A band change size during contractionno, include only the myosin II so it doesn't change
- 27what happens to z disk during contractionshrinks b/c encompasses entire sarcomere
- 28what proteins found in the Z diskcapping protein for the + and - ends of actin to make it stable
- 29where is myosin 2 and myosin 1 found during cytokinesis?myosin 2 found in cleavage furrow
myosin 1 found in edges of each dividing cell - 30what is the basic unit of an IFtetramer
- 31tetramersa non polar unit that makes up IF
- 32polarity and motor proteins of IFdoes not have either
- 33steps in making an IFtetramers -> protofilament -> protofibrils -> IFs
- 34distribution of IFsmostly cytoplasmic but lamins are nuclear
- 35functions of IFsprovide structural support necessary for cell shape
(ie keratins and lamins are IF) - 36keratinslink to e-cadherin and stabilize epithelial cells
- 37laminssupport nuclear membrane
network-linked to nuclear lamina - 38distribution and proposed function of keratins
- 39distribution and proposed function of desmin, GFAP, vimentindesmin = muscle, GFAP = glial, vimentin = mesenchymal (integrity + cell mig)
- 40distribution and proposed function of neurofilaments (NFL, NFM, and NFH)neurons in axon organization
- 41distribution and proposed function of laminsnucleus, nuclear structure and organization
- 42what induces disassembly of IF and prevents reassemblyphosphorylation of serine residues
- 43how are IFs regulatednot regulated by binding+capping proteins like MT and actin... depend on eqm of kinases and phosphatases
- 44exchanging segments in IFproteins within the filament are exchanged- segments in an existing IF can be taken out and replaced w new segments
can remove from the middle - 45disassembly of IFs during mitosisneed to disassemble during mitosis- if you mutate serines you never get disassembly and cells never divide
- 46where tubulin binds GTP, actin binds _ and IFs bind _where tubulin binds GTP, actin binds ATP and IFs do not bind anything
- 47assembly differences b/w MT, actin, IFsMT = regulated from small number of locations
actin = regulated from large number of locations
IFS = assembled into prexisting filaments - 48—
Information
- Description
- midterm Cell Phys 3140 Flashcards on DG - Lecture 10, created by Mary Nguyen on 14/10/2015.
- Created by
- Mary Nguyen
- Views
- 1
- Rating