Myosin II and Myosin V differ in their assembly and function; Myosin II forms bipolar thick filaments to contract actin, while Myosin V transports membrane vesicle cargo along actin filaments. Myosin II interacts with F-actin and microtubules, whereas Myosin V interacts with G-actin and tubulin dimers. Additionally, GTP-Rho activates WASP to bind and activate Arp2/3, leading to branched F-actin networks that facilitate plasma membrane movement.

1. How does myosin II differ from myosin V? Myosin II assembles into bipolar thick filaments to
contract anti-parallel actin filaments whereas myosin V binds a membrane vesicle cargo with its
tail and carries the cargo toward the plus end of a single actin filament. Myosin II walks on
microtubules whereas myosin V walks on tubulin dimers. Myosin II walks on F -actin whereas
myosin walks on g -actin. Myosin II assembles into bipolar thick filaments to contract anti-
parallel microtubules whereas myosin V binds a membrane vesicle cargo with its tail and carries
the cargo toward the plus end of a single microtubule. Question 5 1 pts GTP-rho activates:
WASP which then binds and activates ARP2,3, which nucleates a branched network of F -actin,
which pushes the plasma membrane forward by a thermal ratchet mechanism: Binding of
importins to NLS (nuclear localization signal). Formins which nucleate straight actin filaments
and rho kinase which activates myosin II by phosphorylating myosin regulatory light chain.
Contraction of branched microtubule networks.