Questions With Complete Solutions
a mutation in filamin A gene Correct Answers neurons fail to
migrate during development
A mutation in which gene will result in faster aging? Correct
Answers Lamins
Actin (microfilaments) Correct Answers highly organized
networks of polymers and actin binding proteins.
Persistent length = 13.5micrometers
-responds to local signaling activity
-polarized
-myosin protein motors
Actin Binding Proteins (ABPs) Correct Answers regulate the
stability of F-actin and G-actin
actin-binding proteins Correct Answers regulate the assembly
and disassembly of actin filaments, their cross-linking into
bundles and networks, and their association with other cells
(such as the plasma membrane)
actin-bundling proteins Correct Answers the proteins that
cross-link actin filaments into bundles. usually small rigid
proteins that force the filaments to align closely with one
another.
alpha-actin, filamin, fimbrin, bvillin Correct Answers filament
cross-linking
, Arp 2/3 mediated nucleation model Correct Answers 1. Arp
2/3 Complex binds to sides or (-) end of actin filaments.
2. Nucleation promotion factors delivers G-actin subunits to the
anchored complex.
3. G-actin monomers are added to (+) end of growing filament.
Arp2/3 proteins Correct Answers initiate growth of branched
actin filaments, which play a key role in driving cell movement
at the plasma membrane. The Arp2/3 proteins bind ATP-actin
near the barbed ends of filaments and initiate the formation of a
new branch.
Arp2/3, formin Correct Answers filament initiation and
polymerization
Branched networks characteristics Correct Answers -cell
movement and shape changes
-generate forces when assembled at cell surface
-Arp2/3 complex
-energy is from ATP hydrolysis
- (-) capping proteins
-longer filaments produced
-filaments can change alignment and produce other architectures
-limited force produced
building blocks of cytoskeleton Correct Answers -multiple
copies of a few key pieces that fit together to form larger objects
-can be assembled into a wide range of structures with diverse
properties