Myosin heavy chain kinases play essential roles in Ca2+, but not cAMP, chemotaxis and the natural aggregation of Dictyostelium discoideum

Journal of Cell Science (Impact Factor: 5.43). 08/2012; 125(20). DOI: 10.1242/jcs.112474
Source: PubMed


Behavioral analyses of the deletion mutants of the four known myosin II heavy chain (Mhc) kinases of D. discoideum revealed that all played a minor role in the efficiency of basic cell motility, but none played a role in chemotaxis in a spatial gradient of cAMP generated in vitro. However, each of the two kinases MhckA and MhckC, was essential for chemotaxis in a spatial gradient of Ca(2+), shear induced directed movement, and reorientation in the front of waves of cAMP during natural aggregation. The mutant phenotypes of mhckA(-) and mhckC(-) were highly similar to that of the Ca(2+) channel/receptor mutant iplA(-) and the myosin II phosphorylation mutant 3XALA, which produces constitutively unphosphorylated myosin II. These results demonstrate that IplA, MhckA and MhckC play a selective role in chemotaxis in a spatial gradient of Ca(2+), but not cAMP and suggest that Ca(2+) chemotaxis plays a role in the orientation of cells in the front of cAMP waves during natural aggregation.

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Available from: Daniel F Lusche, Oct 29, 2015
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