The mammalian passenger protein TD-60 is an RCC1 family member with an essential role in prometaphase to metaphase progression.
Passenger proteins migrate from inner centromeres to the spindle midzone during late mitosis, and those described to date are essential both for proper chromosome segregation and for completion of cell cleavage. We have purified and cloned the human passenger protein TD-60, and we here report that it is a member of the RCC1 family and that it binds preferentially the nucleotide-free form of the small G protein Rac1. Using siRNA, we further demonstrate that the absence of TD-60 substantially suppresses overall spindle assembly, blocks cells in prometaphase, and activates the spindle assembly checkpoint. These defects suggest TD-60 may have a role in global spindle assembly or may be specifically required to integrate kinetochores into the mitotic spindle. The latter is consistent with a TD-60 requirement for recruitment of the passenger proteins survivin and Aurora B, and suggests that like other passenger proteins, TD-60 is involved in regulation of cell cleavage.
Mollinari
Cristiana
C
Institut de Biologie Structurale J-P Ebel, CEA-CNRS, 41 rue Jules Horowitz, 38027 Cedex 1, Grenoble, France.
Reynaud
Caroline
C
Martineau-Thuillier
Stephanie
S
Monier
Solange
S
Kieffer
Sylvie
S
Garin
Jerome
J
Andreassen
Paul R
PR
Boulet
Annick
A
Goud
Bruno
B
Kleman
Jean-Philippe
JP
Margolis
Robert L
RL
D000595:Amino Acid Sequence; D002135:Calcium-Binding Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins; D002455:Cell Division; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002875:Chromosomes / Q000378:metabolism; D003001:Cloning, Molecular; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D064246:Mad2 Proteins; D008677:Metaphase; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D012097:Repressor Proteins; D016415:Sequence Alignment; D008941:Spindle Apparatus / Q000378:metabolism; D014407:Tumor Cells, Cultured; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D020662:Guanine Nucleotide Exchange Factors; C577697:MAD2L1 protein, human; D064246:Mad2 Proteins; D009687:Nuclear Proteins; C062521:RCC1 protein, human; C477650:RCC2 protein, human; D034741:RNA, Small Interfering; D012097:Repressor Proteins; D020830:rac1 GTP-Binding Protein