RRC ID 78512
Author Izumi Y, Ohta N, Itoh-Furuya A, Fuse N, Matsuzaki F.
Title Differential functions of G protein and Baz-aPKC signaling pathways in Drosophila neuroblast asymmetric division.
Journal J Cell Biol
Abstract Drosophila melanogaster neuroblasts (NBs) undergo asymmetric divisions during which cell-fate determinants localize asymmetrically, mitotic spindles orient along the apical-basal axis, and unequal-sized daughter cells appear. We identified here the first Drosophila mutant in the Ggamma1 subunit of heterotrimeric G protein, which produces Ggamma1 lacking its membrane anchor site and exhibits phenotypes identical to those of Gbeta13F, including abnormal spindle asymmetry and spindle orientation in NB divisions. This mutant fails to bind Gbeta13F to the membrane, indicating an essential role of cortical Ggamma1-Gbeta13F signaling in asymmetric divisions. In Ggamma1 and Gbeta13F mutant NBs, Pins-Galphai, which normally localize in the apical cortex, no longer distribute asymmetrically. However, the other apical components, Bazooka-atypical PKC-Par6-Inscuteable, still remain polarized and responsible for asymmetric Miranda localization, suggesting their dominant role in localizing cell-fate determinants. Further analysis of Gbetagamma and other mutants indicates a predominant role of Partner of Inscuteable-Galphai in spindle orientation. We thus suggest that the two apical signaling pathways have overlapping but different roles in asymmetric NB division.
Volume 164(5)
Pages 729-38
Published 2004-3-1
DOI 10.1083/jcb.200309162
PII jcb.200309162
PMID 14981094
PMC PMC2172166
MeSH Amino Acid Sequence Animals Animals, Genetically Modified Carrier Proteins / metabolism* Cell Cycle Proteins / metabolism Cell Division / physiology* Cell Polarity Cell Size Cytoskeletal Proteins / genetics Cytoskeletal Proteins / metabolism Drosophila Proteins / metabolism* Drosophila melanogaster / embryology Drosophila melanogaster / physiology* Embryo, Nonmammalian / physiology GTP-Binding Protein alpha Subunits, Gq-G11 / genetics GTP-Binding Protein alpha Subunits, Gq-G11 / metabolism* GTP-Binding Protein beta Subunits / genetics GTP-Binding Protein beta Subunits / metabolism Intracellular Signaling Peptides and Proteins* Isoenzymes / metabolism Macromolecular Substances Molecular Sequence Data Neurons / cytology Neurons / physiology* Neuropeptides Point Mutation Protein Kinase C / metabolism* Protein Subunits / genetics Protein Subunits / metabolism Proteins / genetics Proteins / metabolism Second Messenger Systems / physiology* Spindle Apparatus / metabolism
IF 8.811
Drosophila DGRC#119100