Structural Maintenance Of Chromosomes Protein 4 (SMC4)

Sequence analysis predicted that the 1,202-amino acid CAPC protein lacks the first 80 residues of the frog sequence but is homologous in the middle coiled-coil region. Northern blot analysis detected a 5.0-kb transcript. Western blot and immunoprecipitation analyses showed that CAPC is expressed as a 165-kD soluble nuclear protein throughout the cell cycle in a variety of cell lines and is associated with CAPE in a heterodimeric complex. Immunofluorescence analysis demonstrated that the proteins are associated with condensed chromosomes in mitotic cells and show dense speckles in interphase nuclei. Microinjection of anti-CAPC or anti-CAPE failed to arrest mitosis in metaphase cells, in contrast to antibody to SMC1L1.