Inn1 couples contraction of the actomyosin ring to membrane ingression during cytokinesis in budding yeast.
By rapidly depleting each of the essential budding yeast proteins of unknown function, we identified a novel factor that we call Inn1, which associates with the contractile actomyosin ring at the end of mitosis and is needed for cytokinesis. We show that Inn1 has a C2 domain at the amino terminus of the protein that is required for ingression of the plasma membrane, whereas the remainder of the protein recruits Inn1 to the actomyosin ring. The lethal effects of deleting the INN1 gene can be suppressed by artificial fusion of the C2 domain to other components of the actomyosin ring, restoring membrane ingression on contraction of the actomyosin ring. Our data indicate that recruitment of the C2 domain of Inn1 to the contractile actomyosin ring is crucial for ingression of the plasma membrane during cytokinesis in budding yeast.
Sanchez-Diaz
Alberto
A
Cancer Research U.K., Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester, M20 4BX, UK.
Marchesi
Vanessa
V
Murray
Stephen
S
Jones
Richard
R
Pereira
Gislene
G
Edmondson
Ricky
R
Allen
Terry
T
Labib
Karim
K
D000205:Actomyosin / Q000378:metabolism*; D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D048749:Cytokinesis / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D008938:Mitosis / Q000502:physiology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D040901:Proteomics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000502:physiology / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; C528682:Inn1 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D000205:Actomyosin