bacteria dissemination

control of actin dynamics

ATP increases F actin stability
Arp2/3 complex acts as 2 monomers to increase rate of polymerisation
profilin binds G actin and funnels monomers
formin makes straight actin
ADF/cofilin catalyses depolymerisation

NPFs

nucleation promoting factors
communicate with Arp2/3 via VCA domain

listeria actin comet tail

enables motility
short cross linked filaments
barbed end points toward bacterium
offers protection from autophagy

actA actin treadmilling

binds Arp2/3 and VASP - promotes speed and directionality to favour parallel filament
profilin binds G and promotes ATP exchange
actinin cross links
CapZ prevents fanning
cofilin/ADF maintains G pool

listeria mechanism of intercellular spread

InlC disrupts cell-cell junctions and binds tuba

shigella comet tails - icsA

OM protein with CTD autotransporter
polarises to end of cell
no WCA domain - doesn't bind Arp2/3
glycine rich repeats bind NWASP

shigella icsB

acts as autophagy shield by preventing Atg5 association to the bacteria surface

rickettsia actin comet tail

non branched
Sca2 formin-like = straight filaments
FH1 domain binds profilin-actin and feeds to FH2 which elongates the filament