TY - JOUR
T1 - Mammalian Pins is a conformational switch that links NuMA to heterotrimeric G proteins
AU - Du, Quansheng
AU - Macara, Ian G.
N1 - Funding Information:
We thank Maurine Linder (Washington University, MO) for the Gαi-His 6 expression vector; Duane Compton (Dartmouth University, NH) for anti-NuMA antibodies and the NuMA cDNA; Roger Tsien (UCSD) for mRFP1; Atsushi Miyawaki (RIKEN, Japan) for Venus; Doug Bayliss (University of Virginia) for the GRK2 C terminus, Gαi, and Gαi1(Q204L); Mark Rasenick (University of Illinois, Chicago) for Gαs-GFP; Keith Mostov (UCSF) for MDCK T23 cell line; and Juergen Knoblich (IMP, Vienna, Austria) for the Pins cDNAs. We also thank Anne Spang (Tübingen) for valuable comments on the manuscript. This work was supported by grants PO1CA40042 and R01 GM070902 from the National Institutes of Health, DHHS.
PY - 2004/11/12
Y1 - 2004/11/12
N2 - During asymmetric cell divisions, mitotic spindles align along the axis of polarization. In invertebrates, spindle positioning requires Pins or related proteins and a G protein α subunit. A mammalian Pins, called LGN, binds Gαi and also interacts through an N-terminal domain with the microtubule binding protein NuMA. During mitosis, LGN recruits NuMA to the cell cortex, while cortical association of LGN itself requires the C-terminal Gα binding domain. Using a FRET biosensor, we find that LGN behaves as a conformational switch: in its closed state, the N and C termini interact, but NuMA or Gαi can disrupt this association, allowing LGN to interact simultaneously with both proteins, resulting in their cortical localization. Overexpression of Gαi or YFP-LGN causes a pronounced oscillation of metaphase spindles, and NuMA binding to LGN is required for these spindle movements. We propose that a related switch mechanism might operate in asymmetric cell divisions in the fly and nematode.
AB - During asymmetric cell divisions, mitotic spindles align along the axis of polarization. In invertebrates, spindle positioning requires Pins or related proteins and a G protein α subunit. A mammalian Pins, called LGN, binds Gαi and also interacts through an N-terminal domain with the microtubule binding protein NuMA. During mitosis, LGN recruits NuMA to the cell cortex, while cortical association of LGN itself requires the C-terminal Gα binding domain. Using a FRET biosensor, we find that LGN behaves as a conformational switch: in its closed state, the N and C termini interact, but NuMA or Gαi can disrupt this association, allowing LGN to interact simultaneously with both proteins, resulting in their cortical localization. Overexpression of Gαi or YFP-LGN causes a pronounced oscillation of metaphase spindles, and NuMA binding to LGN is required for these spindle movements. We propose that a related switch mechanism might operate in asymmetric cell divisions in the fly and nematode.
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U2 - 10.1016/j.cell.2004.10.028
DO - 10.1016/j.cell.2004.10.028
M3 - Article
C2 - 15537540
AN - SCOPUS:8344271193
SN - 0092-8674
VL - 119
SP - 503
EP - 516
JO - Cell
JF - Cell
IS - 4
ER -