PLAP-1/asporin inhibits activation of BMP receptor via its leucine-rich repeat motif.
We previously identified the novel gene, periodontal ligament-associated protein-1 (PLAP-1)/asporin and reported that PLAP-1/asporin inhibited bone morphogenetic protein-2 (BMP-2)-induced cytodifferentiation of periodontal ligament (PDL) cells probably by direct interaction with BMP-2. Here, we elucidated the detailed regulatory mechanism of this protein on BMP-2-induced cytodifferentiation of PDL cells. Recombinant PLAP-1/asporin inhibited BMP-2-induced cytodifferentiation of PDL cells and competitively prevented BMP-2 from binding to the BMP receptor-IB (BMPR-IB), resulting in inhibition of BMP-dependent activation of Smad proteins. The induction of mutation to the leucine-rich repeat (LRR) motif, especially LRR5, within PLAP-1/asporin rescued the inhibitory effect of PLAP-1/asporin on BMP-2. By contrast, a 26-amino acid peptide in the PLAP-1/asporin LRR5 sequence inhibited BMP-2 activity. Our findings indicate that PLAP-1/asporin inhibits BMP-2-induced differentiation of PDL cells resulting from inactivation of the BMP-2 signaling pathway and that LRR, especially LRR5 of PLAP-1/asporin, plays an important role in the PLAP-1/asporin-BMP-2 interaction.
Tomoeda
M
M
Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
Yamada
S
S
Shirai
H
H
Ozawa
Y
Y
Yanagita
M
M
Murakami
S
S
D020816:Amino Acid Motifs / Q000235:genetics; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D052005:Bone Morphogenetic Protein Receptors, Type I / Q000037:antagonists & inhibitors* / Q000378:metabolism; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002460:Cell Line; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D007930:Leucine / Q000737:chemistry; D051379:Mice; D009154:Mutation; D010766:Phosphorylation; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D020449:Repetitive Sequences, Amino Acid / Q000235:genetics; D051785:Smad Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology
C511592:Aspn protein, mouse; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016326:Extracellular Matrix Proteins; D011994:Recombinant Proteins; D051785:Smad Proteins; D016212:Transforming Growth Factor beta; D052005:Bone Morphogenetic Protein Receptors, Type I; D007930:Leucine