Figure 2.

Biological activities of wild-type and mutant BMPR-II. (A) Structure and location of mutations of WT, SH, and mutant BMPR-II used in the following experiments. Numbers indicate amino acid positions. Mutations are denoted by asterisks. Missense mutations in extracellular (E1) and kinase (K1 and K2) domain mutants and substituted amino acid residues are shown. Cytoplasmic tail mutants (T1 and T2) have frameshift or nonsense mutations resulting in truncated tails. (B and C) Transcriptional activation by wild-type and mutant BMPR-II. p3TP-Lux reporter gene was cotransfected into R-mutant mink lung epithelial cells with ALK-3 and wild-type and/or mutant forms of BMPR-II as indicated, and cells were stimulated with or without BMP-2 (100 ng/ml for B and 50 ng/ml for C). Luciferase activity was normalized against cotransfected sea pansy luciferase activity. Expression of cotransfected BMPR-II mutants was confirmed by immunoblotting of cell lysates with anti-FLAG antibodies (C, right).