Rabs cycle between a GTP-bound active form and a GDP-bound inactive form, and active Rabs promote membrane trafficking by recruiting specific effector molecules, including lipid kinases, phosphatases, coat adaptors, BAR proteins, kinesin motor adaptors, dynamin adaptors, myosin motors, actin regulatory proteins, tethering factors, and phospholipid binding proteins.
The cytoskeleton controls interactions in the mitochondrial network, facilitated by a host of membrane fission/fusion proteins, motor and adaptor proteins.
However, the confinement can be due to different mechanisms, e.g. the elastic interaction of the melanosome with the microtubule through the molecular motor and adaptor molecules, or trapping in a crowded microenvironment.
This supports the idea that the KIF5A TRAK2 interaction is multivalent and could act to ensure stable motor-cargo interaction during intracellular trafficking; dimerization of both motor and adaptor molecules further enhances this stability (Fig. 6).
With the exception of the axonal-specific tether syntaphilin, the same motor and adaptor proteins and regulatory mechanisms that govern neuronal mitochondrial transport appear to be employed for mitochondrial transport in non-neuronal cell types [ 97, 102].
Furthermore, the dynein molecular motor and its adaptor BICD2 could also be involved in messenger RNA transport (Swan and Suter, 1996).
But other proteins are likely involved as well including E3 ligases, deubiquitylating enzymes (DUBs), adaptor, scaffold, motor and vesicular coat proteins.
This accumulation depends on microtubules, the minus-end directed motor Dynein and the adaptor proteins BicD and Egalitarian (Egl) themselves (Theurkauf et al. 1993; Carpenter 1994; Ran et al. 1994; Bolívar et al. 2001; Navarro et al. 2004).
Although very informative, these studies did not include physiological cargo, cargo adaptors, and motor co-factors that could potentially modulate motor behaviour.
