Lis1 regulates dynein by sterically blocking its mechanochemical cycle.
Regulation of cytoplasmic dynein's motor activity is essential for diverse eukaryotic functions, including cell division, intracellular transport, and brain development. The dynein regulator Lis1 is known to keep dynein bound to microtubules; however, how this is accomplished mechanistically remains unknown. We have used three-dimensional electron microscopy, single-molecule imaging, biochemistry, and in vivo assays to help establish this mechanism. The three-dimensional structure of the dynein-Lis1 complex shows that binding of Lis1 to dynein's AAA+ ring sterically prevents dynein's main mechanical element, the 'linker', from completing its normal conformational cycle. Single-molecule experiments show that eliminating this block by shortening the linker to a point where it can physically bypass Lis1 renders single dynein motors insensitive to regulation by Lis1. Our data reveal that Lis1 keeps dynein in a persistent microtubule-bound state by directly blocking the progression of its mechanochemical cycle.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.
Katerina
K
Toropova
Department of Cell Biology, Harvard Medical School, Boston, United States.
Sirui
S
Zou
Department of Cell Biology, Harvard Medical School, Boston, United States.
Anthony J
AJ
Roberts
Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.
William B
WB
Redwine
Department of Cell Biology, Harvard Medical School, Boston, United States.
Brian S
BS
Goodman
Department of Cell Biology, Harvard Medical School, Boston, United States.
Samara L
SL
Reck-Peterson
Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.
Andres E
AE
Leschziner
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001696:Biomechanical Phenomena; D004398:Dyneins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004722:Endoribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D000255:Adenosine Triphosphate; D004722:Endoribonucleases; C499539:PAC1 protein, S cerevisiae; C000596030:DYN1 protein, S cerevisiae; D004398:Dyneins
Lis1; S. cerevisiae; biochemistry; biophysics; dynein; electron microscopy; microtubules; structural biology; structure