Figure 3.

Solubility properties identify Ce-MAN1 as an integral membrane protein. C. elegans nuclei were extracted for 30 min in PBS or PBS containing one of the following reagents: 1 M NaCl, 1% Triton X-100, 1 M NaCl plus 1% Triton X-100, NaOH pH 11, or 8 M urea. After extraction, the supernatants (S) and residual pellets (P) were separated by centrifugation, and proteins were separated by 12% SDS-PAGE and analyzed by immunoblotting with the use of antibodies specific for Ce-MAN1 (C-terminal peptide) and Ce-lamin (see MATERIALS AND METHODS). The smaller band in the 8 M urea supernatant lane represents a degradation product of lamin; Ce-MAN1 degradation was not detected in the same extract. The positions of Ce-MAN1 and Ce-lamin are indicated by arrows at left. Similar results were obtained for Ce-emerin.