Fig. 4. Functions of spectraplakins. Spectraplakins have at least four different known or proposed modes of function in a cell, depicted here in the Drosophila context: (1) crosslinking of cytoskeletal filaments; (2) linking the cytoskeleton to plasma membrane proteins; (3) organising the interaction between the cortical cytoskeleton and plasma membrane proteins to generate membrane subdomains; and (4) acting as a scaffold protein that recruits signalling proteins to sites of cytoskeletal activity.