Figure 5.

Overexpression of the Cas mutant lacking Crk binding ability inhibits axon elongation of granule cells. (A) Cas mutants with domain deletion or mutation. ΔSH3, deletion of the SH3 domain; ΔSD deletion of a cluster of tyrosine phosphorylation sites; ΔYDxP, deletion of YDxP motifs; mSBD, double mutations RLGSSPP and FDYV at the Src binding domain. (B) Confocal images of cerebellar granule cells expressing Cas mutants. Cerebellar granule cells were double-transfected by electroporation with a Cas mutant with an EGFP vector soon after dissociation of cerebellar cells. The cells were stained with the antibody against HA 48 h after plating. Bar, 100 μm. (C) Average length of the axons in the EGFP and Cas mutants coexpressing cells. (D) Percentage of transfected cells with axon length more than 200 μm. Cerebellar granule cells (DIV1) were transfected with Cas mutants using the calcium phosphate method. Cells were fixed, stained with the antibody against HA, and observed at DIV2. Data are indicated as mean ± SEM. Values in the parentheses above the column indicate the number of the transfected cells from at least three independent experiments. ***p < 0.001, compared with the EGFP control (t test).