Cytoskeleton I Flashcards
Cytoskeletal structures are _______ polymers
Cytoskeletal structures are NON-COVALENT polymers
Intermediate filaments surround ____, extend to ____, and at _____ + _____ junctions.
They are controlled by ____.
Role in protection from ______, also role in _____ and controlling ______. No known associated ____.
Basic structure is _-chained _______ that assembles to form ____ _____ (therefore, not ____).
____ and ____ ends are ____; _______ region is interrupted by ___ domains.
Examples: ____, ____, ____.
Intermediate filaments surround NUCLEUS, extend to CELL PERIPHERY, and at CELL-CELL + CELL-ECM junctions.
They are controlled by PHOSPHORYLATION.
Role in protection from MECHANICAL STRESS, also role in CELL SIGNALING and controlling GENE REGULATORY NETWORKS. No known associated MOTORS.
Basic structure is TWO-chained COILED-COIL that assembles to form ANTIPARALLEL-TETRAMER (therefore, not POLAR).
N and C TERMINAL ends are GLOBULAR; COILED-COIL region is interrupted by LINKER domains.
Examples: KERATIN, NEUROFILAMENTS, NUCLEAR LAMINS.
Actin filaments (F-actin) are polymers of _______, that contains a bound ____ or ____.
Filament is ___.
Plus (or _____) end is the ____ growing end. The minus (or ____) end is the ____ growing end.
Filament is _____.
Actin binding proteins modify ______.
Energy of hydrolysis is ______.
Actin filaments (F-actin) are polymers of G-ACTIN, that contains a bound ATP OR ADP.
Filament is POLAR.
Plus (or BARBED) end is the FAST growing end. The minus (or POINTED) end is the SLOW growing end.
Filament is HELICAL.
Actin binding proteins modify FILAMENT DYNAMICS.
Energy of hydrolysis is NOT REQUIRED FOR POLYMERIZATION.
Microtubules are polymers of _____ arranged in tubules with __ ______.
Binds ___/____.
Tubules are _____.
Energy of hydrolysis is _______.
Dynamics and state of assembly can be regulated by ____.
For microtubule to reach the cell periphery, ______ inhibit catastrophies..
Microtubules are important for ___, ____/___, ___ and ____.
Microtubules are polymers of a/B TUBULINE arranged in tubules with 13 PROTOFILAMENTS.
Binds GDP/GTP.
Tubules are POLAR.
Energy of hydrolysis is NOT REQUIRED FOR POLYMERIZATION.
Dynamics and state of assembly can be regulated by MICROTUBULE BPS.
For microtubule to reach the cell periphery, + TIP PROTEINS inhibit catastrophies.
Microtubules are important for VESICLE TRANSPORT, MITOTIC SPINDLE, CILIA/FLAGELLA, CENTRIOLE, BASAL BODIES.
Primary cilium is _____, usually _ per cell. Found in ____ organelles. Central player in ______ signaling pathways.
Primary cilium is NON-MOTILE, usually 1 per cell. Found in SENSORY organelles. Central player in DEVELOPMENTAL signaling pathways.
Centrosome is organized around ______. Contains ______ ring complex that nucleates the ________ of microtubules and caps the _ ends.
This causes _ end to be oriented towards the cell periphery.
Centrioles duplicate beginning in _ phase of miotsis.
Centrosome is organized around A PAIR OF CENTRIOLES. Contains GAMMA-TUBULIN ring complex that nucleates the 13 PROTOFILAMENTS of microtubules and caps the MINUS ends.
This causes PLUS end to be oriented towards the cell periphery.
Centrioles duplicate beginning in S phase of miotsis.
Tau protein is a ____
Tau protein is a MICROTUBULE ASSOCIATED PROTEIN (MAP)
Phalloidin binds and ____ ___ filaments. Found in _____.
Phalloidin binds and STABILIZES ACTIN filaments. Found in DEATH ANGEL MUSHROOM.
Colchicine ______ microtubules. Found in the _____.
Colchicine DEPOLYMERIZES microtubules. Found in the AUTUMN CROCUS.
Taxol binds and _____ microtubules. Found in _____, and is usually used in _____ drugs.
Taxol binds and STABILIZES microtubules. Found in PACIFIC YEW, and is usually used in ANTI-CANCER drugs.
Chemotaxis of neutrophil:
-They chase bacteria by utilizing ___ polymerization at the ______ and uses ____-dependent contractions of the tail.
Chemotaxis of neutrophil:
-They chase bacteria by utilizing ACTIN polymerization at the LEADING EDGE and uses MYOSIN-II-dependent contractions of the tail.
How does actin polymerization alone provide force for cell motilty?
-_____ complex ___ filaments from the ___ of actin filaments, making complex _____ structures.
- Other mechanisms: ____ more actin filaments
- ____ existing filaments to create more barbed ends
- form ____ from existing filaments
How does actin polymerization alone provide force for cell motilty?
-ARP2/3 complex NUCLEATES filaments from the SIDES of actin filaments, making complex BRANCHED structures.
- Other mechanisms: NUCLEATE more actin filaments
- SEVER existing filaments to create more barbed ends
- form BRANCHES from existing filaments
____-dependent signaling cascade regulates dendritic nucleation
- _____ activation required for nucleation of acitn polymerization.
- Activators are downstream in ___ family of small _____ signaling cascades.
- Localizes ____ at the ___ ____, site of protrusion of ______.
RHO-dependent signaling cascade regulates dendritic nucleation
- ARP2/3 activation required for nucleation of acitn polymerization.
- Activators are downstream in RHO family of small GTPASES signaling cascades.
- Localizes ACTIVATION at the CELL MEMBRANE, site of protrusion of LAMELLIPODIM.
Arp2/3-dependent polymerization is involved in:
- _____ migration to sites of infection
- _____ healing
- invasion of _____
- certain ____ infections
- _____-dependent endocytosis
Arp2/3-dependent polymerization is involved in:
- NEUTROPHIL migration to sites of infection
- WOUND healing
- invasion of METASTATIC CANCER CELLS
- certain BACTERIAL infections
- CLATHIRIN-dependent endocytosis
Listeria infects intestinal epithelium and hijacks _____ ______ machinery.
Protein homologous to ____/____ on the bacterial surface activates ______ complex.
____ filaments polymerize, forming a ____ that propels the ____ through the cytoplasm.
Listeria infects intestinal epithelium and hijacks ARP2/3 POLYMERIZATION machinery.
Protein homologous to WASP/SCAR on the bacterial surface activates ARP2/3 complex.
ACTIN filaments polymerize, forming a COMET that propels the BACTERIUM through the cytoplasm.
