Distribution of HeLa cells polypeptides in cytoplasts and karyoplasts.

The polypeptide composition of cytoplasts and karyoplasts prepared form HeLa cells prelabelled with [35S]-methionine and enucleated with Cytochalasin B has been analyzed using high resolution two dimensional gel electrophoresis (IEF and NEPHGE). Of the 259 major proteins followed in this study we have identified 73 polypeptides (30 acidic(IEF) and 43 basic (NEPHGE)) that are present mainly in karyoplasts. One of these polypeptides (IEF 49) has previously been shown to be a polypeptide marker for cycling cells. A total of 59 polypeptides (27 acidic and 32 basic) were found to be present mainly in cytoplasts. Many polypeptides (109 acidic and 18 basic) including Y and beta-actin (60% in cytoplasts), beta-tubulin (60% in cytoplasts), vimentin (75% in cytoplasts) and alpha-actinin (65% in cytoplasts) were found to be present in both cellular fragments. These results could be of value in assigning the cellular distribution of potential regulatory proteins.