Structure-specific recognition protein 1 facilitates microtubule growth and bundling required for mitosis.
Tight regulation of microtubule (MT) dynamics is essential for proper chromosome movement during mitosis. Here we show, using mammalian cells, that structure-specific recognition protein 1 (SSRP1) is a novel regulator of MT dynamics. SSRP1 colocalizes with the spindle and midbody MTs, and associates with MTs both in vitro and in vivo. Purified SSRP1 facilitates tubulin polymerization and MT bundling in vitro. Knockdown of SSRP1 inhibits the growth of MTs and leads to disorganized spindle structures, reduction of K-fibers and midbody fibers, disrupted chromosome movement, and attenuated cytokinesis in vivo. These results demonstrate that SSRP1 is crucial for MT growth and spindle assembly during mitosis.
Zeng
Shelya X
SX
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, MS-0051, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
Li
Yanping
Y
Jin
Yetao
Y
Zhang
Qi
Q
Keller
David M
DM
McQuaw
Carolyn M
CM
Barklis
Eric
E
Stone
Stacie
S
Hoatlin
Maureen
M
Zhao
Yingming
Y
Lu
Hua
H
D002460:Cell Line; D020090:Chromosome Segregation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D046529:Microscopy, Electron, Transmission; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D008938:Mitosis; D011485:Protein Binding; D008941:Spindle Apparatus / Q000378:metabolism; D035602:Transcriptional Elongation Factors / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; C073537:SSRP1 protein, human; D035602:Transcriptional Elongation Factors