Drosophila Ric-8 regulates Gαi cortical localization to promote Gαi-dependent planar orientation of the mitotic spindle during asymmetric cell division

Localization and activation of heterotrimeric G proteins have a crucial role during asymmetric cell division. The asymmetric division of the Drosophila sensory precursor cell (pI) is polarized along the antero-posterior axis by Frizzled signalling and, during this division, activation of Gαi depends on Partner of Inscuteable (Pins). We establish here that Ric-8, which belongs to a family of guanine nucleotide-exchange factors for Gαi, regulates cortical localization of the subunits Gαi and Gβ13F. Ric-8, Gαi and Pins are not necessary for the control of the antero-posterior orientation of the mitotic spindle during pI cell division downstream of Frizzled signalling, but they are required for maintainance of the spindle within the plane of the epithelium. On the contrary, Frizzled signalling orients the spindle along the antero-posterior axis but also tilts it along the apico-basal axis. Thus, Frizzled and heterotrimeric G-protein signalling act in opposition to ensure that the spindle aligns both in the plane of the epithelium and along the tissue polarity axis.

[1]  Y. Barral,et al.  Spindle asymmetry: a compass for the cell. , 2003, Trends in cell biology.

[2]  J. Knoblich,et al.  Bazooka recruits Inscuteable to orient asymmetric cell divisions in Drosophila neuroblasts , 1999, Nature.

[3]  Yuh Nung Jan,et al.  Asymmetric cell division , 1998, Nature.

[4]  I. Macara,et al.  Mammalian Pins Is a Conformational Switch that Links NuMA to Heterotrimeric G Proteins , 2004, Cell.

[5]  G. Schoenwolf,et al.  Role of nonrandomly oriented cell division in shaping and bending of the neural plate , 1997, The Journal of comparative neurology.

[6]  A. Gilman,et al.  Mammalian Ric-8A (Synembryn) Is a Heterotrimeric Gα Protein Guanine Nucleotide Exchange Factor* , 2003, The Journal of Biological Chemistry.

[7]  Y. Jan,et al.  Two types of asymmetric divisions in the Drosophila sensory organ precursor cell lineage , 2000, Nature Cell Biology.

[8]  M. Gho,et al.  Lethal Giant Larvae Controls the Localization of Notch-Signaling Regulators Numb, Neuralized, and Sanpodo in Drosophila Sensory-Organ Precursor Cells , 2005, Current Biology.

[9]  Anthony A Hyman,et al.  Asymmetric cell division in C. elegans: cortical polarity and spindle positioning. , 2004, Annual review of cell and developmental biology.

[10]  E. Knust,et al.  Bazooka provides an apical cue for Inscuteable localization in Drosophila neuroblasts , 1999, Nature.

[11]  P. Wedegaertner,et al.  Heterotrimer Formation, Together with Isoprenylation, Is Required for Plasma Membrane Targeting of Gβγ* , 2003, The Journal of Biological Chemistry.

[12]  M. Gho,et al.  Revisiting the Drosophila microchaete lineage: a novel intrinsically asymmetric cell division generates a glial cell. , 1999, Development.

[13]  R. Adams.  Metaphase Spindles Rotate in the Neuroepithelium of Rat Cerebral Cortex , 1996, The Journal of Neuroscience.

[14]  M. Gho,et al.  Frizzled signalling controls orientation of asymmetric sense organ precursor cell divisions in Drosophila , 1998, Nature.

[15]  Scott E. Fraser,et al.  Planar cell polarity signalling controls cell division orientation during zebrafish gastrulation , 2004, Nature.

[16]  Nicholas H. Brown,et al.  Rotation and asymmetry of the mitotic spindle direct asymmetric cell division in the developing central nervous system , 1999, Nature Cell Biology.

[17]  J. Knoblich,et al.  Heterotrimeric G Proteins Direct Two Modes of Asymmetric Cell Division in the Drosophila Nervous System , 2001, Cell.

[18]  Lesilee S. Rose,et al.  LET-99 opposes Gα/GPR signaling to generate asymmetry for spindle positioning in response to PAR and MES-1/SRC-1 signaling , 2003, Development.

[19]  F. Schweisguth,et al.  Unequal segregation of Neuralized biases Notch activation during asymmetric cell division. , 2003, Developmental cell.

[20]  A. Shevchenko,et al.  A protein complex containing Inscuteable and the Gα-binding protein Pins orients asymmetric cell divisions in Drosophila , 2000, Current Biology.

[21]  C. Doe,et al.  The tumour-suppressor genes lgl and dlg regulate basal protein targeting in Drosophila neuroblasts , 2000, Nature.

[22]  William A. Harris,et al.  In Vivo Time-Lapse Imaging of Cell Divisions during Neurogenesis in the Developing Zebrafish Retina , 2003, Neuron.

[23]  Y. Jan,et al.  Asymmetric distribution of numb protein during division of the sensory organ precursor cell confers distinct fates to daughter cells , 1994, Cell.

[24]  Y. Bellaïche,et al.  The planar cell polarity protein Strabismus promotes Pins anterior localization during asymmetric division of sensory organ precursor cells in Drosophila , 2003, Development.

[25]  M. Gotta,et al.  Control of Embryonic Spindle Positioning and Gα Activity by C. elegans RIC-8 , 2004, Current Biology.

[26]  J. Knoblich,et al.  Heterotrimeric G Proteins New Tricks for an Old Dog , 2004, Cell.

[27]  M. Bergo,et al.  Membrane trafficking of heterotrimeric G proteins via the endoplasmic reticulum and Golgi. , 2002, Molecular biology of the cell.

[28]  Yohanns Bellaïche,et al.  Frizzled regulates localization of cell-fate determinants and mitotic spindle rotation during asymmetric cell division , 2000, Nature Cell Biology.

[29]  N. Fuse,et al.  Differential functions of G protein and Baz–aPKC signaling pathways in Drosophila neuroblast asymmetric division , 2004, The Journal of cell biology.

[30]  P. Bryant,et al.  The Partner of Inscuteable/Discs-Large Complex Is Required to Establish Planar Polarity during Asymmetric Cell Division in Drosophila , 2001, Cell.

[31]  K. Miller,et al.  RIC-8 (Synembryn): a novel conserved protein that is required for G(q)alpha signaling in the C. elegans nervous system. , 2000, Neuron.

[32]  X. Morin,et al.  Analysis of partner of inscuteable, a Novel Player of Drosophila Asymmetric Divisions, Reveals Two Distinct Steps in Inscuteable Apical Localization , 2000, Cell.

[33]  H. Hamm,et al.  Heterotrimeric G proteins. , 1996, Current opinion in cell biology.

[34]  Y. Peterson,et al.  Selective Interaction of AGS3 with G-proteins and the Influence of AGS3 on the Activation State of G-proteins* , 2001, The Journal of Biological Chemistry.

[35]  S. Zaffran,et al.  The Heterotrimeric Protein Go Is Required for the Formation of Heart Epithelium in Drosophila , 1999, The Journal of cell biology.

[36]  P. Gönczy,et al.  RIC-8 Is Required for GPR-1/2-Dependent Gα Function during Asymmetric Division of C. elegans Embryos , 2004, Cell.

[37]  V. Katanaev,et al.  Trimeric G Protein-Dependent Frizzled Signaling in Drosophila , 2005, Cell.

[38]  P. Adler,et al.  Asymmetric cell division: Plane but not simple , 2001, Current Biology.

[39]  Kenneth G. Miller,et al.  RIC-8 (Synembryn) A Novel Conserved Protein that Is Required for Gqα Signaling in the C. elegans Nervous System , 2000, Neuron.

[40]  M. Gho,et al.  The glial cell undergoes apoptosis in the microchaete lineage of Drosophila , 2003, Development.

[41]  L. Luo,et al.  Regulating Axon Branch Stability The Role of p190 RhoGAP in Repressing a Retraction Signaling Pathway , 2001, Cell.

[42]  N. Perrimon,et al.  Localization of apical epithelial determinants by the basolateral PDZ protein Scribble , 2000, Nature.

[43]  Y. Jan,et al.  Bazooka is required for localization of determinants and controlling proliferation in the sensory organ precursor cell lineage in Drosophila , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[44]  M. Bownes,et al.  Locomotion defects, together with Pins, regulates heterotrimeric G-protein signaling during Drosophila neuroblast asymmetric divisions. , 2005, Genes & development.