Mitotic apparatus and nucleoli compartmentalization of 50,000-dalton type II regulatory subunit of cAMP-dependent protein kinase in estrogen receptor negative MDA-MB-231 human breast cancer cells.

摘要: Affinity purified RI and RII antibodies of regulatory subunits (R) type I (RI) II (RII) cAMP-dependent protein kinase were utilized to determine the immunological characterization specific compartmentalization R in estrogen receptor negative MDA-MB-231 human breast cancer cells. The 8-azido-(32P)-cAMP binding analysis cell extracts exhibited 47,000- 50,000-dalton cAMP proteins. antibodies, by immunoprecipitation, detected proteins, respectively. 47,000-dalton was identified as it showed a similar molecular weight bovine on SDS-polyacrylamide gel electrophoresis. Although did not co-migrate with heart 54,000-dalton RII, cells since specifically precipitated antibody but antibody. An indirect immunofluorescence revealed that during different phases growth cells, compartmentalized mitotic spindle nucleoli whereas exhibit distributed throughout components. These results suggest role(s) at nuclei