Fig. 7. Domains in Shot L(A) required for axon extension. Neuronal expression of Shot L(A)-GFP rescues (+) motor and sensory axon extension defects in shot mutants. Shot L(A) contains an N-terminal actin-binding domain (ABD, black box), a central rod domain consisting of a plakin-like region (gray box), 22 spectrin repeats (hatched box), and a C-terminal domain with Ca²⁺- (EF-hand) and microtubule- (GAS2) binding motifs. Shot L(C)-GFP contains no ABD and has no rescue activity (–). Derivatives of Shot L(A)-GFP that lack the EF-hand, GAS2 homology or the spectrin repeat sequences were tested for motor and sensory axon extension activity. Shot L(C) and Shot L(A)-GAS2 also have no rescue activity when co-expressed.