Ablation of Csk in neural crest lineages causes corneal anomaly by deregulating collagen fibril organization and cell motility.
Src family kinases (SFKs) have been implicated in the regulation of cell motility. To verify their in vivo roles during development, we generated mutant mice in which Csk, a negative regulator of SFKs, was inactivated in neural crest lineages using the Protein zero promoter in a Cre-loxP system. Inactivation of Csk caused deformities in various tissues of neural crest origins, including facial dysplasia and corneal opacity. In the cornea, the stromal collagen fibril was disorganized and there was an overproduction of collagen 1a1 and several metalloproteases. The corneal endothelium failed to overlie the central region of the eye and the peripheral endothelium displayed a disorganized cytoskeleton. Corneal mesenchymal cells cultured from mutant mice showed attenuated cell motility. In these cells, p130 Crk-associated substrate (Cas) was hyperphosphorylated and markedly downregulated. The expression of a dominant negative Cas (Cas Delta SD) could suppress the cell motility defects. Fluorescence resonance energy transfer analysis revealed that activation of Rac1 and Cdc42 was depolarized in Csk-inactivated cells, which was restored by the expression of either Csk or Cas Delta SD. These results demonstrate that the SFKs/Csk circuit plays crucial roles in corneal development by controlling stromal organization and by ensuring cell motility via the Cas-Rac/Cdc42 pathways.
Takatsuka
Atsuko
A
Department of Oncogene Research, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Yagi
Reiko
R
Koike
Masato
M
Oneyama
Chitose
C
Nada
Shigeyuki
S
Schmedt
Christian
C
Uchiyama
Yasuo
Y
Okada
Masato
M
D000818:Animals; D000081247:CSK Tyrosine-Protein Kinase; D002465:Cell Movement / Q000502:physiology; D003094:Collagen / Q000378:metabolism*; D003315:Cornea / Q000002:abnormalities* / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D008648:Mesoderm / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D018993:Myelin P0 Protein / Q000235:genetics; D009432:Neural Crest / Q000166:cytology* / Q000201:enzymology*; D010641:Phenotype; D011401:Promoter Regions, Genetic; D011505:Protein-Tyrosine Kinases / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D034622:RNA Interference; D050717:Retinoblastoma-Like Protein p130 / Q000378:metabolism; D019061:src-Family Kinases
D018993:Myelin P0 Protein; C493838:Rbl2 protein, mouse; D050717:Retinoblastoma-Like Protein p130; D003094:Collagen; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases