cytoskeletal system Flashcards
(16 cards)
Prokayote similarities of MT, MF, IF
MT-FtsZ
MF- MreB
IF- Crescentin
Structure of MT
Hollow tube with a wall consisting of 13 protofilaments
MT assembly steps
- tubular dimmers combine into oligomers (nucleation)
- oligomers form linear chains of protofilaments
- protofilaments make sheets, sheets with 13 close into tube
- elongation via addition of tubular heterodimers
The GTP bound to the b subunit is hydrolyzed to GDP after the heterodimer is added to the MT T/F
T
Antimitotic drugs
disrupts mitotic spindle of dividing cells
effects of colchicine and taxol on MT assembly
C- binds to the GTP binding domain
Taxol- binds to MT and stabilizes then, arrests dividing cells in mitosis
roles of MF
- contractile fibres in muscle cells
- cell movements
- developing and maintaining cell shape (cell cortex, microvilli)
2 groups of actin
- muscle specific (a)
2. non muscle actins (b+y)
MF assembly
monomers of g actin add on plus side of F actin MF
3 drugs that affect polymerization of MF
Cytochalasins- prevents addition of new monomers
Latrunculin A- sequestering actin monomers
Phalloidin- stabilizes MFs
What does Arp2/3 do
WASP activates arp2/3 complex and nucleation on the sides of filaments occur
How does listeria infect organisms
attaches to host after binding to E cadherin
Spreads to nearby cells by producing a comet tail of polymerized actin
Function of IF
structural or tension bearing (most stable but dynamic)
T/F IF subunit proteins are tissue specific
T
IF assembly
dimers align laterally to form tetramer
Tetramer aligns to form protofilaments
fully assembled IF is 8 protofilaments thick
IF disease
Epidermolysis bulls simplex (keratin mutation)
