Figure 1

Processing features of proSP-C^WT or proSP-C^I73T. (A) Immunoblotting of total cell lysates with tag-specific antibodies. Cell lysates obtained from MLE-12 cells stably expressing fusion protein of proSP-C with an N-terminal HA-tag (left panel), transiently transfected cells expressing fusion protein of proSP-C with an N-terminal EGFP (EGFP-C1, middle panel) or a C-terminal EGFP (EGFP-N1, right panel), present with several bands corresponding to different proSP-C processing intermediates, in which the tag sequence is retained. (B) Based on the size of the bands, the projected corresponding intermediate species of the fusion constructs are depicted. The cleavage sites are only estimates due to the limited resolution of the technique. EGFP-C1 (band #5) and EGFP-N1 (band #9) are expressed as a full-length product of 48 kDa, HA-SP-C (band #1) of size 22 kDa.