The G-protein regulatory (GPR) motif-containing Leu-Gly-Asn-enriched protein (LGN) and Gialpha3 influence cortical positioning of the mitotic spindle poles at metaphase in symmetrically dividing mammalian cells.
We addressed the role of the G-protein regulatory (GPR) motif-containing Leu-Gly-Asn-enriched protein (LGN) and G-proteins (Gialpha3) in the positioning of the spindle pole during mammalian cell division. Immunocytochemistry indicated that both LGN and Gialpha3 co-localized at the spindle pole and at the midbody and the cell cortex during the different phases of mitosis. In marked contrast to the positioning of the spindle pole at metaphase midway between the cell cortex and the metaphase plate, the spindle pole was juxtaposed with the cell cortex at metaphase following increased expression of Gialpha3 and LGN. This repositioning of the spindle pole required the interaction of LGN with Gialpha. The influence of LGN and Gialpha3 on the cortical positioning of the spindle pole likely reflects either stronger pulling forces on the spindle pole exerted from the cell cortex or increased pushing forces exerted on the spindle pole from the mitotic spindle indicating that these events are regulated by GPR motif-containing proteins and G-proteins independent of asymmetry.
Blumer
Joe B
JB
Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido St., New Orleans, LA 70112, USA.
Kuriyama
Ryoko
R
Gettys
Thomas W
TW
Lanier
Stephen M
SM
D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D001216:Asparagine / Q000032:analysis; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation; D005998:Glycine / Q000032:analysis; D047908:Intracellular Signaling Peptides and Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D007930:Leucine / Q000032:analysis; D008677:Metaphase / Q000235:genetics / Q000502:physiology*; D008938:Mitosis / Q000235:genetics / Q000502:physiology*; D008941:Spindle Apparatus / Q000502:physiology*
D047908:Intracellular Signaling Peptides and Proteins; D001216:Asparagine; D019204:GTP-Binding Proteins; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D007930:Leucine; D005998:Glycine