Myosin V processivity: multiple kinetic pathways for head-to-head coordination.
Myosin V, a double-headed molecular motor, transports organelles within cells by walking processively along actin, a process that requires coordination between the heads. To understand the mechanism underlying this coordination, processive runs of single myosin V molecules were perturbed by varying nucleotide content. Contrary to current views, our results show that the two heads of a myosin V molecule communicate, not through any one mechanism but through an elaborate system of cooperative mechanisms involving multiple kinetic pathways. These mechanisms introduce redundancy and safeguards that ensure robust processivity under differing physiologic demands.
Baker
Josh E
JE
Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA.
Krementsova
Elena B
EB
Kennedy
Guy G
GG
Armstrong
Amy
A
Trybus
Kathleen M
KM
Warshaw
David M
DM
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D007700:Kinetics; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D024701:Myosin Type V / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018411:Spodoptera / Q000166:cytology
D008164:Luminescent Proteins; D020409:Molecular Motor Proteins; D011994:Recombinant Proteins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D024701:Myosin Type V