Many cytoskeletal proteins associate with the hela cytoskeleton during translation in vitro

Observations that cytoskeletal proteins assemble in vivo close to the time and site of synthesis have been confirmed and extended by an in vitro translation system. HeLa cytoskeletons prepared with Triton in a translation-extraction buffer without reticulocyte or wheat germ lysate efficiently incorporate 35S-methionine into polypeptides, and are stable during this translation. Cytoskeletal proteins translated in this way associate with the HeLa cytoskeleton independent of the concentration of soluble proteins. These associations are puromycin-resistant before the proteins are complete; the protein associations made in vitro show only minor differences from those made in vivo. The protein associations are not simply a consequence of protein solubility in the buffers used, as the associations require initiation in vivo. These results indicate that many cytoskeletal proteins associate with the cytoskeleton during translation.