Fig. 4.
MT motors and myosins in apical trafficking. MTs are organized into two populations in polarized epithelial cells: stable cortical MTs with the minus ends facing apically, and dynamic MTs that originate at the MTOC, with the plus ends facing apically. Actin filaments have very different organizations under the apical surface (apical actin), under the lateral surface (lateral actin) and at the perinuclear region (peri-Golgi actin). The minus-end kinesin KIFC3 has been implicated in the transport of influenza HA, a lipid-raft-associated protein (route 1). Dynein participates in the transport of rhodopsin from the TGN (route 2). The plus-end kinesin KIF5B participates in the transport of p75 (route 4). Myosin-II and myosin-VI have been implicated in basolateral transport from the TGN and CRE, respectively. Myosin-IA has been implicated in post-Golgi transport, transcytosis and transport across the apical actin. E, endocytic route; Ed, endocytic degradative route; Er, endocytic recycling route.