The thesis research presented here focused on studies of a novel myosin II heavy chain kinase D (MHCK D) expressed in Dictyostelium discoideum cells. MHCK D is made up of four distinct domains: a short coiled-coil region (Coil), a region rich in serine, asparagine, proline, & glutamine residues (SNPQ), a kinase catalytic domain (Cat), and a WD-repeat segment (WD). A major component of this project was to amplify the Catalytic and WD repeat domains (Cat-WD) from genomic DNA. The Cat-WD truncation of MHCK D was cloned into pTX-GFP & pTX-Flag plasmids for expression in Dictyostelium cells. The recombinant plasmids were electroporated into Dictyostelium cells to over-express the fusion protein (GFP, or flag-tagged). To determine if MHCK D does phosphorylate the Myosin heavy chain, which in turn drives bi-polar filament disassembly, the phenotype of cells over-expressing the Cat-WD domain were compared to the phenotype of Myosin II-null cells and non-recombinant wild type cells. Cells over-expressing the Cat-WD domain from MHCK D, showed a phenotype similar to Myosin II-null cells, indicating that the Cat-WD domain plays a role in Myosin II bi-polar filament disassembly resulting from phosphorylation of the myosin heavy chain. Another aim of the thesis research focused on expression of the mhkd gene during the multi-cellular development cycle of Dictyostelium, using Reverse Transcriptase-PCR (RT-PCR). The results indicate that mhkd is expressed throughout the multi-cellular development cycle, as well as during the vegetative growth phase of Dictyostelium. In summary, the results reveal that the Cat-WD domain of MHCK D drives Myosin II bi-polar filament disassembly leading to defects in cytokinesis, and is expressed in both vegetative cells as well as cells undergoing the multi-cellular development cycle. These studies provide a basis for future research focused on activation, localization, and substrate targeting of MHCK D.