PMID- 20199682
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20110714
LR  - 20211020
IS  - 1756-0500 (Electronic)
IS  - 1756-0500 (Linking)
VI  - 3
DP  - 2010 Mar 3
TI  - Identification of a new mechanism for targeting myosin II heavy chain 
      phosphorylation by Dictyostelium myosin heavy chain kinase B.
PG  - 56
LID - 10.1186/1756-0500-3-56 [doi]
AB  - BACKGROUND: Heavy chain phosphorylation plays a central role in regulating myosin 
      II bipolar filament assembly in Dictyostelium, as well as in higher eukaryotic 
      nonmuscle cells. Our previous work has demonstrated that the WD-repeat domain of 
      Dictyostelium myosin II heavy chain kinase B (MHCK-B), unlike its counterpart in 
      MHCK-A, is not absolutely required for targeting of the kinase to phosphorylate 
      MHC. Thus, we tested the hypothesis that an asparagine-rich and structurally 
      disordered region that is unique to MHCK-B can by itself function in substrate 
      targeting. FINDINGS: Biochemical assays comparing the activities of full-length 
      MHCK-B, a truncation lacking only the WD-repeat domain (B-Delta-WD), and a 
      truncation lacking both the N-rich region and the WD-repeat domain (B-Delta-N-WD) 
      revealed that the N-rich region targets MHCK-B to phosphorylate MHC in a manner 
      that leads to bipolar filament disassembly. This targeting is physiologically 
      relevant since cellular over-expression of the B-Delta-WD truncation, but not the 
      B-Delta-N-WD truncation, leads to dramatically reduced levels of myosin II 
      filament assembly and associated defects in cytokinesis and multicellular 
      development. CONCLUSIONS: The results presented here demonstrate that an 
      intrinsically unstructured, and asparagine-rich, region of a MHCK-B can mediate 
      specific targeting of the kinase to phosphorylate myosin II heavy chain. This 
      targeting involves a direct binding interaction with myosin II filaments. In 
      terms of regulating myosin bipolar filament assembly, our results suggest that 
      factors affecting the activity of this unique region of MHCK-B could allow for 
      regulation of MHCK-B in a manner that is distinct from the other MHCKs in 
      Dictyostelium.
FAU - Underwood, Julie
AU  - Underwood J
AD  - Department of Biology, University of North Carolina at Greensboro, Greensboro, 
      North Carolina, USA. p_steiml@uncg.edu.
FAU - Greene, Jonathan
AU  - Greene J
FAU - Steimle, Paul A
AU  - Steimle PA
LA  - eng
GR  - R15 GM066789/GM/NIGMS NIH HHS/United States
GR  - R15 GM066789-02/GM/NIGMS NIH HHS/United States
PT  - Journal Article
DEP - 20100303
PL  - England
TA  - BMC Res Notes
JT  - BMC research notes
JID - 101462768
PMC - PMC2838905
EDAT- 2010/03/05 06:00
MHDA- 2010/03/05 06:01
PMCR- 2010/03/03
CRDT- 2010/03/05 06:00
PHST- 2009/07/21 00:00 [received]
PHST- 2010/03/03 00:00 [accepted]
PHST- 2010/03/05 06:00 [entrez]
PHST- 2010/03/05 06:00 [pubmed]
PHST- 2010/03/05 06:01 [medline]
PHST- 2010/03/03 00:00 [pmc-release]
AID - 1756-0500-3-56 [pii]
AID - 10.1186/1756-0500-3-56 [doi]
PST - epublish
SO  - BMC Res Notes. 2010 Mar 3;3:56. doi: 10.1186/1756-0500-3-56.