p37/UBXN2B regulates spindle orientation by limiting cortical NuMA recruitment via PP1/Repo-Man

J Cell Biol. 2018 Feb 5;217(2):483-493. doi: 10.1083/jcb.201707050. Epub 2017 Dec 8.


Spindle orientation determines the axis of division and is crucial for cell fate, tissue morphogenesis, and the development of an organism. In animal cells, spindle orientation is regulated by the conserved Gαi-LGN-NuMA complex, which targets the force generator dynein-dynactin to the cortex. In this study, we show that p37/UBXN2B, a cofactor of the p97 AAA ATPase, regulates spindle orientation in mammalian cells by limiting the levels of cortical NuMA. p37 controls cortical NuMA levels via the phosphatase PP1 and its regulatory subunit Repo-Man, but it acts independently of Gαi, the kinase Aurora A, and the phosphatase PP2A. Our data show that in anaphase, when the spindle elongates, PP1/Repo-Man promotes the accumulation of NuMA at the cortex. In metaphase, p37 negatively regulates this function of PP1, resulting in lower cortical NuMA levels and correct spindle orientation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Antigens, Nuclear / metabolism*
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins / metabolism*
  • HeLa Cells
  • Humans
  • Nuclear Matrix-Associated Proteins / metabolism*
  • Nuclear Proteins / metabolism*
  • Receptors, Neuropeptide Y / metabolism*
  • Spindle Apparatus / metabolism*
  • Tumor Cells, Cultured


  • Adaptor Proteins, Signal Transducing
  • Antigens, Nuclear
  • CDCA2 protein, human
  • Carrier Proteins
  • Cell Cycle Proteins
  • NUMA1 protein, human
  • Nuclear Matrix-Associated Proteins
  • Nuclear Proteins
  • Receptors, Neuropeptide Y
  • p37 protein, human
  • neuropeptide Y4 receptor