Actin/Cytoskeletal Flashcards
G-actin
monomer form of actin, globular
F-actin
filamentous form of actin, linear
ATP bound
closed, stable conformation in which assembly is promoted
nucleation
process of starting an actin filament; begins with 3 actin monomers - recruits formin which stabilizes the (+) end and allows for adding of additional monomers
Arp2/3 complex
initiates branching on actin filaments at a 70 degree angle
branching networks of actin are found here
lamellipodia, cortical actin
linear bundled actin is found here
filopodia, microvilli, stress fibers
phalloidin
from death cap mushroom, is cell toxic because it binds F-actin and hyperstabilizes it - causing inability to disassemble the filament
fascin
cross linking protein that bundles parallel filaments in filopodia
filopodia
can grow/shrink based on actin assembly and disassembly - is not anchored strongly to actin cytoskeleton so can disassemble quickly for movement
microvilli
more stable than filopodia, attached to the cortical actin cytoskeleton so cannot shrink. Functions in sensation in gut epithelial cells
cortical actomyosin
used in wound healing (purse string)
ActA protein
bacterial protein that allows pathogens to hijack the actin network and use it to speed thru cells by activating Arp2/3 rapid assembly
cytoskeleton of RBCs
spectrin based actin matrix that uses ankyrin and band-3, among other proteins, to anchor to plasma membrane;
mutations in spectrin lead to ovalocytes, mutations in ankyrin/band-3 lead to spherocytes
dystrophin
protein that attaches stressed muscle cells to supporting extracellular matrix; mutations in this cause muscular dystrophy - the worst type of which is Duchennes.
