See additional references for the role of contractile proteins in chromatin remodeling throughout the cell cycle.
Also, there is a paper there entitled “Endosymbionts” that discusses how endosymbionts may survive by either escaping into the host-cell cytoplasm or from phagolysosomes. If apoptosis is aborted prematurely by disrupting the cascade, ancient endosymbionts may take this opportunity to escape the cell as best they can.
Actin and tubulin are associated with movement of mitochondria and chloroplasts within cells (reference). These kinds of proteins could also be used to transport other endosymbionts as well.