Nonmuscle myosin II molecules carry out a wide variety of functions within cells. There are three nonmuscle myosin II genes. We are using optical trapping nanometry to study the interaction of nonmuscle myosin IIB with actin. When phosphorylated this myosin has long attachment times as would be expected from such a slow myosin, but that it does not move processively in the optical trap and shows only attachments and detachments without stepping in a single molecule motility assay in which actin is bound to the surface and the interaction with fluorescently-labeled myosin is observed. We have expressed full length nonmuscle myosins IIA and IIB and have characterized their steady state MgATPase properties. We have examined the filament structure of these myosins using negative staining electron microscopy and find that both form short bipolar filaments of similar length and thickness. These short filaments move processively in the above mentioned motility assay. We will use a combination of solution studies and electron microscopy to study the assembly mechanism for these myosins and observe their interaction with actin. We have also expressed mutant forms of nonmuscle myosin IIA corresponding to naturally occuring, disease causing mutations that give rise to giant platelet disorders and will characterize the effect of these mutations on myosin function and filament assembly.

Project Start
Project End
Budget Start
Budget End
Support Year
32
Fiscal Year
2011
Total Cost
$478,064
Indirect Cost
Name
National Heart, Lung, and Blood Institute
Department
Type
DUNS #
City
State
Country
Zip Code
Liu, Xiong; Billington, Neil; Shu, Shi et al. (2017) Effect of ATP and regulatory light-chain phosphorylation on the polymerization of mammalian nonmuscle myosin II. Proc Natl Acad Sci U S A 114:E6516-E6525
Bruun, Kyle; Beach, Jordan R; Heissler, Sarah M et al. (2017) Re-evaluating the roles of myosin 18A? and F-actin in determining Golgi morphology. Cytoskeleton (Hoboken) 74:205-218
Baird, Michelle A; Billington, Neil; Wang, Aibing et al. (2017) Local pulsatile contractions are an intrinsic property of the myosin 2A motor in the cortical cytoskeleton of adherent cells. Mol Biol Cell 28:240-251
Heissler, Sarah M; Sellers, James R (2016) Various Themes of Myosin Regulation. J Mol Biol 428:1927-46
Chen, Pei-Wen; Jian, Xiaoying; Heissler, Sarah M et al. (2016) The Arf GTPase-activating Protein, ASAP1, Binds Nonmuscle Myosin 2A to Control Remodeling of the Actomyosin Network. J Biol Chem 291:7517-26
Heissler, Sarah M; Sellers, James R (2016) Kinetic Adaptations of Myosins for Their Diverse Cellular Functions. Traffic 17:839-59
Vasquez, Claudia G; Heissler, Sarah M; Billington, Neil et al. (2016) Drosophila non-muscle myosin II motor activity determines the rate of tissue folding. Elife 5:
Liu, Xiong; Shu, Shi; Billington, Neil et al. (2016) Mammalian Nonmuscle Myosin II Binds to Anionic Phospholipids with Concomitant Dissociation of the Regulatory Light Chain. J Biol Chem 291:24828-24837
Heissler, Sarah M; Chinthalapudi, Krishna; Sellers, James R (2015) Kinetic characterization of the sole nonmuscle myosin-2 from the model organism Drosophila melanogaster. FASEB J 29:1456-66
Bond, Lisa M; Sellers, James R; McKerracher, Lisa (2015) Rho kinase as a target for cerebral vascular disorders. Future Med Chem 7:1039-53

Showing the most recent 10 out of 27 publications