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XB-ART-44795
Dev Biol April 1, 2012; 364 (1): 42-55.

The cytoplasmic tyrosine kinase Arg regulates gastrulation via control of actin organization.

Bonacci G , Fletcher J , Devani M , Dwivedi H , Keller R , Chang C .


Abstract
Coordinated cell movements are crucial for vertebrate gastrulation and are controlled by multiple signals. Although many factors are shown to mediate non-canonical Wnt pathways to regulate cell polarity and intercalation during gastrulation, signaling molecules acting in other pathways are less investigated and the connections between various signals and cytoskeleton are not well understood. In this study, we show that the cytoplasmic tyrosine kinase Arg modulates gastrulation movements through control of actin remodeling. Arg is expressed in the dorsal mesoderm at the onset of gastrulation, and both gain- and loss-of-function of Arg disrupted axial development in Xenopus embryos. Arg controlled migration of anterior mesendoderm, influenced cell decision on individual versus collective migration, and modulated spreading and protrusive activities of anterior mesendodermal cells. Arg also regulated convergent extension of the trunk mesoderm by influencing cell intercalation behaviors. Arg modulated actin organization to control dynamic F-actin distribution at the cell-cell contact or in membrane protrusions. The functions of Arg required an intact tyrosine kinase domain but not the actin-binding motifs in its carboxyl terminus. Arg acted downstream of receptor tyrosine kinases to regulate phosphorylation of endogenous CrkII and paxillin, adaptor proteins involved in activation of Rho family GTPases and actin reorganization. Our data demonstrate that Arg is a crucial cytoplasmic signaling molecule that controls dynamic actin remodeling and mesodermal cell behaviors during Xenopus gastrulation.

PubMed ID: 22305799
PMC ID: PMC3294122
Article link: Dev Biol
Grant support: [+]

Species referenced: Xenopus laevis
Genes referenced: abl1 abl2 actl6a chrd.1 crk fn1 gsc mapk1 myod1 nog pxn rho rho.2 sox2 tbxt ventx1.2 wnt11
Antibodies: Crk Ab1 Crk Ab2 Mapk1 Ab15 Pxn Ab4
Morpholinos: abl2 MO1 abl2 MO2

Phenotypes: Xla Wt + abl2 (fig.2.a) [+]

Article Images: [+] show captions
References [+] :
Ataliotis, PDGF signalling is required for gastrulation of Xenopus laevis. 1995, Pubmed, Xenbase