title: Novel myosin heavy chain kinase involved in disassembly of myosin II filaments and efficient cleavage in mitotic dictyostelium cells.
abstract: We have cloned a full-length cDNA encoding a novel myosin II heavy chain kinase (mhckC) from Dictyostelium. Like other members of the myosin heavy chain kinase family, the mhckC gene product, MHCK C, has a kinase domain in its N-terminal half and six WD repeats in the C-terminal half. GFP-MHCK C fusion protein localized to the cortex of interphase cells, to the cleavage furrow of mitotic cells, and to the posterior of migrating cells. These distributions of GFP-MHCK C always corresponded with that of myosin II filaments and were not observed in myosin II-null cells, where GFP-MHCK C was diffusely distributed in the cytoplasm. Thus, localization of MHCK C seems to be myosin II-dependent. Cells lacking the mhckC gene exhibited excessive aggregation of myosin II filaments in the cleavage furrows and in the posteriors of the daughter cells once cleavage was complete. The cleavage process of these cells took longer than that of wild-type cells. Taken together, these findings suggest MHCK C drives the disassembly of myosin II filaments for efficient cytokinesis and recycling of myosin II that occurs during cytokinesis.
authors.affiliation: Gene Function Research Laboratory, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8562, Japan. a-nagasaki@aist.go.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Nagasaki
authors.forename: Go
authors.initials: G
authors.lastname: Itoh
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Yumura
authors.forename: Taro Q P
authors.initials: TQ
authors.lastname: Uyeda
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000096:biosynthesis* / Q000502:physiology*; D020134:Catalytic Domain; D002455:Cell Division; D018076:DNA, Complementary / Q000378:metabolism; D004023:Dictyostelium / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008938:Mitosis; D008954:Models, Biological; D008957:Models, Genetic; D008969:Molecular Sequence Data; D024462:Myosin Type II / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D018076:DNA, Complementary; D008164:Luminescent Proteins; D015800:Protozoan Proteins; D049452:Green Fluorescent Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C033142:myosin-heavy-chain kinase; D024462:Myosin Type II