PUBLICATION

IQGAP3 Is Essential for Cell Proliferation and Motility During Zebrafish Embryonic Development

Authors
Fang, X., Zhang, B., Thisse, B., Bloom, G.S., Thisse, C.
ID
ZDB-PUB-150820-4
Date
2015
Source
Cytoskeleton (Hoboken, N.J.)   72(8): 422-33 (Journal)
Registered Authors
Thisse, Bernard, Thisse, Christine
Keywords
Danio rerio, IQGAP3, cell motility, cell proliferation, convergent extension, embryonic development
MeSH Terms
  • Animals
  • Cell Adhesion
  • Cell Movement
  • Embryo, Nonmammalian/metabolism
  • Morphogenesis*
  • Receptors, Growth Factor/physiology*
  • Zebrafish/embryology
  • Zebrafish/metabolism*
  • Zebrafish Proteins/metabolism*
  • ras GTPase-Activating Proteins/metabolism*
PubMed
26286209 Full text @ Cytoskeleton
Abstract
IQGAPs are scaffolding proteins that regulate actin assembly, exocyst function, cell motility, morphogenesis, adhesion and division. Vertebrates express 3 family members: IQGAP1, IQGAP2 and IQGAP3. IQGAP1 is known to stimulate nucleation of branched actin filaments through N-WASP and the Arp2/3 complex following direct binding to cytoplasmic tails of ligand-activated growth factor receptors, including EGFR, VEGFR2 and FGFR1. By contrast, little is known about functions of IQGAP2 or IQGAP3. Using in situ hybridization on whole mount zebrafish (Danio rerio) embryos, we show that IQGAP1 and IQGAP2 are associated with discrete tissues and organs, while IQGAP3 is mainly expressed in proliferative cells throughout embryonic and larval development. Morpholino knockdowns of IQGAP1 and IQGAP2 have little effect on embryo morphology while loss of function of IQGAP3 affects both cell proliferation and cell motility. IQGAP3 morphant phenotypes are similar to those resulting from overexpression of dominant negative forms of Ras or of Fibroblast Growth Factor Receptor 1 (FGFR1), suggesting that IQGAP3 plays a role in FGFR1-Ras-ERK signaling. In support of this hypothesis, dominant negative forms of FGFR1 or Ras could be rescued by co-injection of zebrafish IQGAP3 mRNA, strongly suggesting that IQGAP3 acts as a downstream regulator of the FGFR1-Ras signaling pathway. This article is protected by copyright. All rights reserved.
Genes / Markers
Figures
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Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping
Errata and Notes