DNA molecules encoding BMP receptor proteins

1. An isolated DNA molecule comprising a DNA sequence encoding a BMP receptor protein, wherein the DNA sequence comprises nucleotides 61 to 1656 of SEQ ID NO: 1.

2. An isolated DNA molecule comprising a DNA sequence encoding a BMP receptor protein, wherein the DNA sequence comprises nucleotides encoding for amino acids 24 to 532 of SEQ ID NO: 2.

3. An isolated host cell transformed with the DNA molecule of claim 1 .

4. An isolated host cell transformed with the DNA molecule of claim 2 .

5. An isolated DNA molecule having a sequence encoding a truncated BMP receptor protein which is characterized by the ability to bind to BMP-2 or BMP-4 in a binding assay, said DNA molecule comprising a DNA sequence selected from the group consisting of:

(a) nucleotide 61 to 507 of SEQ ID NO: 1;

(b) nucleotides encoding amino acids 1 to 149 of SEQ ID NO: 2; and

(c) nucleotides encoding amino acids 24 to 149 of SEQ ID NO:2.

6. An isolated host cell transformed with the DNA molecule of claim 5 .

7. A vector comprising a DNA molecule of claim 5 in operative association with an expression control sequence therefor.

8. A method for producing a purified truncated BMP receptor protein, said method comprising the steps of:

(a) culturing in a culture medium a host cell transformed with a DNA sequence according to claim 5 , comprising a nucleotide sequence encoding a truncated BMP receptor protein; and

(b) recovering and purifying said truncated BMP receptor protein from the culture medium.

9. A method for producing a truncated BMP receptor protein, said method comprising the steps of:

(a) culturing in a culture medium a host cell according to claim 6 , comprising a truncated nucleotide sequence encoding the ligand binding domain of a BMP receptor protein; and

(b) recovering and purifying said BMP receptor protein from the culture medium.

10. An isolated DNA molecule comprising the DNA sequence of CFK1-23a deposited under ATCC accession number 69378.