RAB6 binding domain (RBD) found in kinesin-like proteins KIF20A, KIF20B, and similar proteins
This family includes kinesin-like proteins KIF20A and KIF20B. KIF20A (also called GG10_2, mitotic kinesin-like protein 2 (MKlp2), Rab6-interacting kinesin-like protein, or rabkinesin-6) is a mitotic kinesin required for chromosome passenger complex (CPC)-mediated cytokinesis. Following phosphorylation by PLK1 (polo-like kinase 1), it is involved in recruitment of PLK1 to the central spindle. KIF20A interacts with guanosine triphosphate (GTP)-bound forms of RAB6A and RAB6B. It may act as a motor required for the retrograde RAB6 regulated transport of Golgi membranes and associated vesicles along microtubules. KIF20A has a microtubule plus-end-directed motility. KIF20B (also called cancer/testis antigen 90 (CT90), kinesin family member 20B, kinesin-related motor interacting with PIN1, or M-phase phosphoprotein 1 (MPP1)) is a plus-end-directed motor enzyme that is required for completion of cytokinesis. It is required for proper midbody organization and abscission in polarized cortical stem cells. KIF20B plays a role in the regulation of neuronal polarization by mediating the transport of specific cargoes. It participates in the mobilization of SHTN1 and in the accumulation of PIP3 in the growth cone of primary hippocampal neurons in a tubulin and actin-dependent manner. In the developing telencephalon, KIF20B cooperates with SHTN1 to promote both the transition from the multipolar to the bipolar stage and the radial migration of cortical neurons from the ventricular zone toward the superficial layer of the neocortex. This model corresponds to a conserved domain in the KIF20A subfamily, that shows RAB6 binding ability and has been called the RAB6 binding domain (RBD). KIF20A-RBD is a dimer composed of two parallel alpha helices that form a right-handed coiled-coil additionally stabilized by an inter-helical cysteine bridge.
Jiyao W et al.(2023). "The conserved domain database in 2023.",