scholarly journals Structure of the Dictyostelium Myosin-II Heavy Chain Kinase A (MHCK-A) α-kinase domain apoenzyme reveals a novel autoinhibited conformation

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Qilu Ye ◽  
Yidai Yang ◽  
Laura van Staalduinen ◽  
Scott William Crawley ◽  
Linda Liu ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Myosin Ii ◽  
Kinase Domain ◽  
Dictyostelium Myosin ◽  
Kinase A

scholarly journals Crystal Structure of the  -Kinase Domain of Dictyostelium Myosin Heavy Chain Kinase A

2010 ◽  
Vol 3 (111) ◽  
pp. ra17-ra17 ◽  
Author(s):  
Q. Ye ◽  
S. W. Crawley ◽  
Y. Yang ◽  
G. P. Cote ◽  
Z. Jia
Keyword(s):  
Crystal Structure ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Kinase Domain ◽  
Dictyostelium Myosin ◽  
Myosin Heavy Chain Kinase ◽  
Kinase A

scholarly journals Novel Myosin Heavy Chain Kinase Involved in Disassembly of Myosin II Filaments and Efficient Cleavage in MitoticDictyostelium Cells

2002 ◽  
Vol 13 (12) ◽  
pp. 4333-4342 ◽  
Author(s):  
Akira Nagasaki ◽  
Go Itoh ◽  
Shigehiko Yumura ◽  
Taro Q.P. Uyeda
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Myosin Ii ◽  
Kinase Domain ◽  
Cleavage Furrow ◽  
Wild Type ◽  
Daughter Cells ◽  
Cleavage Process ◽  
Interphase Cells ◽  
Myosin Heavy Chain Kinase

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, themhckC 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.

scholarly journals Myosin heavy-chain kinase A from Dictyostelium possesses a novel actin-binding domain that cross-links actin filaments

2006 ◽  
Vol 395 (2) ◽  
pp. 373-383 ◽  
Author(s):  
Misty Russ ◽  
Daniel Croft ◽  
Omar Ali ◽  
Raquel Martinez ◽  
Paul A. Steimle
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Actin Filaments ◽  
Myosin Ii ◽  
Coiled Coil ◽  
Actin Binding ◽  
Coiled Coil Domain ◽  
Cross Links ◽  
Myosin Heavy Chain Kinase ◽  
Kinase A

Myosin heavy-chain kinase A (MHCK A) catalyses the disassembly of myosin II filaments in Dictyostelium cells via myosin II heavy-chain phosphorylation. MHCK A possesses a ‘coiled-coil’-enriched domain that mediates the oligomerization, cellular localization and actin-binding activities of the kinase. F-actin (filamentous actin) binding by the coiled-coil domain leads to a 40-fold increase in MHCK A activity. In the present study we examined the actin-binding characteristics of the coiled-coil domain as a means of identifying mechanisms by which MHCK A-mediated disassembly of myosin II filaments can be regulated in the cell. Co-sedimentation assays revealed that the coiled-coil domain of MHCK A binds co-operatively to F-actin with an apparent KD of approx. 0.5 μM and a stoichiometry of approx. 5:1 [actin/C(1–498)]. Further analyses indicate that the coiled-coil domain binds along the length of the actin filament and possesses at least two actin-binding regions. Quite surprisingly, we found that the coiled-coil domain cross-links actin filaments into bundles, indicating that MHCK A can affect the cytoskeleton in two important ways: (1) by driving myosin II-filament disassembly via myosin II heavy-chain phosphorylation, and (2) by cross-linking/bundling actin filaments. This discovery, along with other supporting data, suggests a model in which MHCK A-mediated bundling of actin filaments plays a central role in the recruitment and activation of the kinase at specific sites in the cell. Ultimately this provides a means for achieving the robust and highly localized disruption of myosin II filaments that facilitates polarized changes in cell shape during processes such as chemotaxis, cytokinesis and multicellular development.

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