'Shed' furin: mapping of the cleavage determinants and identification of its C-terminus.
The human endoprotease furin is involved in the proteolytic maturation of the precursor molecules of a wide variety of bioactive proteins. Despite its localization in the membranes of the trans-Golgi system by means of a transmembrane domain, it has repeatedly been reported to form a C-terminally truncated, naturally secreted form referred to as 'shed' furin. In order to identify the cleavage site, internal deletion mutants of increasing size, N-terminal to Leu(708), and subsequently individual amino acid substitutions were introduced, and Arg(683) was identified as the prime determinant for shedding. MS analysis determined Ser(682) as the C-terminus of shed furin, suggesting that monobasic cleavage may occur N-terminal to Arg(683). Alteration of Arg(683) directs the shedding mechanism to alternative cleaving sites previously unused.
Biomedical Research Center, Hyland-Immuno Division, Baxter Healthcare, Uferstr. 15, 2304 Orth/Donau, Austria.
B
B
Plaimauer
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G
Mohr
W
W
Wernhart
M
M
Himmelspach
F
F
Dorner
U
U
Schlokat
D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry; D002460:Cell Line; D045683:Furin; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion; D012694:Serine / Q000737:chemistry; D013381:Subtilisins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
D012694:Serine; D001120:Arginine; D013381:Subtilisins; D045683:Furin