Targeting of microtubule motors to specific cargo is an active area of research. Nuclei migrate to specific locations of a cell during many developmental events such as fertilization, establishment of polarity, and cell division. The C. elegans KASH protein UNC-83 specifically localizes to the outer nuclear membrane where it is required for nuclear migration in embryonic hypodermal Hyp7 cells. UNC-83 and its partner SUN protein form a bridge across the nuclear envelope, connecting the cytoskeleton to the nuclear lamina. We show that UNC-83 is a nuclear-specific cargo adaptor to recruit both Kinesin-1 and Dynein to the nuclear envelope. A yeast two-hybrid screen confirmed by GST pull-downs identified the kinesin light chain KLC-2 and three dynein regulators (NudE homolog NUD-2, BicaudalD homologue BICD-1, and dynein light chain DLC-1) as UNC-83 interacting proteins. KLC-2 interacts with the kinesin heavy chain UNC-116 to form conventional kinesin. klc-2 and unc-116 mutant animals had a nuclear migration defect similar to unc-83 mutant animals. Immunofluorescence showed that UNC-116 and KLC-2 co-localize in part with UNC-83 at the nuclear envelope. bicd-1(RNAi) caused a weak nuclear migration defect that was enhanced in bicd-1(RNAi); nud-2(ok949) animals, suggesting that BICD-1 and NUD-2 function in parallel pathways. Further experiments showed that the egalitarian homologue EGAL-1 functions in a complex with BICD-1 and DLC-1. dlc-1(RNAi) is lethal, but in rare escapers, weak defects in nuclear migration were observed. In the second complex, NUD-2 interacts with LIS-1, which is also required for nuclear migration. Yeast two-hybrid results and functional deletion analysis indicate that two separate domains of UNC-83 interact with kinesin and dynein. These data suggest a model where UNC-83 acts as the cargo-specific adaptor between the outer nuclear membrane and the microtubule motors kinesin and dynein. In this model kinesin functions as the major force generator during nuclear migration, while dynein is involved in regulation. This model is supported by our finding that a KLC-2::KASH construct targets to the nuclear membrane and rescues nuclear migration in an unc-83 mutant background. Hyp7 nuclear migration is therefore an excellent model to study the regulation of dynein and kinesin driven cargo movement. Current studies include an analysis of the microtubule cytoskeleton structure in real time during Hyp7 nuclear migration in wild-type and mutant embryos.