%0 Journal Article
%T Motor domain phosphorylation increases nucleotide exchange and turns MYO6 into a faster and stronger motor.
%A de Jonge JJ
%A Graw A
%A Kargas V
%A Batters C
%A Montanarella AF
%A O'Loughlin T
%A Johnson C
%A Arden SD
%A Warren AJ
%A Geeves MA
%A Kendrick-Jones J
%A Zaccai NR
%A Kröss M
%A Veigel C
%A Buss F
%J Nat Commun
%V 15
%N 1
%D 2024 Aug 7
%M 39112473
%F 17.694
%R 10.1038/s41467-024-49898-3
%X Myosin motors perform many fundamental functions in eukaryotic cells by providing force generation, transport or tethering capacity. Motor activity control within the cell involves on/off switches, however, few examples are known of how myosins regulate speed or processivity and fine-tune their activity to a specific cellular task. Here, we describe a phosphorylation event for myosins of class VI (MYO6) in the motor domain, which accelerates its ATPase activity leading to a 4-fold increase in motor speed determined by actin-gliding assays, single molecule mechanics and stopped flow kinetics. We demonstrate that the serine/threonine kinase DYRK2 phosphorylates MYO6 at S267 in vitro. Single-molecule optical-tweezers studies at low load reveal that S267-phosphorylation results in faster nucleotide-exchange kinetics without change in the working stroke of the motor. The selective increase in stiffness of the acto-MYO6 complex when proceeding load-dependently into the nucleotide-free rigor state demonstrates that S267-phosphorylation turns MYO6 into a stronger motor. Finally, molecular dynamic simulations of the nucleotide-free motor reveal an alternative interaction network within insert-1 upon phosphorylation, suggesting a molecular mechanism, which regulates insert-1 positioning, turning the S267-phosphorylated MYO6 into a faster motor.