Gremlin1 preferentially binds to bone morphogenetic protein-2 (BMP-2) and BMP-4 over BMP-7.
Gremlin (Grem1) is a member of the DAN family of secreted bone morphogenetic protein (BMP) antagonists. Bone morphogenetic protein-7 (BMP-7) mediates protective effects during renal fibrosis associated with diabetes and other renal diseases. The pathogenic mechanism of Grem1 during diabetic nephropathy (DN) has been suggested to be binding and inhibition of BMP-7. However, the precise interactions between Grem1, BMP-7 and other BMPs have not been accurately defined. In the present study, we show the affinity of Grem1 for BMP-7 is lower than that of BMP-2 and BMP-4, using a combination of surface plasmon resonance and cell culture techniques. Using kidney proximal tubule cells and HEK (human embryonic kidney)-293 cell Smad1/5/8 phosphorylation and BMP-dependent gene expression as readouts, Grem1 consistently demonstrated a higher affinity for BMP-2>BMP-4>BMP-7. Cell-associated Grem1 did not inhibit BMP-2- or BMP-4-mediated signalling, suggesting that Grem1-BMP-2 binding occurred in solution, preventing BMP receptor activation. These data suggest that Grem1 preferentially binds to BMP-2 and this may be the dominant complex in a disease situation where levels of Grem1 and BMPs are elevated.
*Centre for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland, U.K.
Rachel H
RH
Church
*Centre for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland, U.K.
Arjun
A
Krishnakumar
†UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
Annika
A
Urbanek
‡Astra Zeneca, Mölndal, Gothenburg, Sweden.
Stefan
S
Geschwindner
§Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, U.K.
Julie
J
Meneely
†UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
Alessandro
A
Bianchi
‡Astra Zeneca, Mölndal, Gothenburg, Sweden.
Barbro
B
Basta
*Centre for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland, U.K.
Sean
S
Monaghan
§Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, U.K.
Christopher
C
Elliot
‡Astra Zeneca, Mölndal, Gothenburg, Sweden.
Maria
M
Strömstedt
†UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
Neil
N
Ferguson
†UCD Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
Finian
F
Martin
*Centre for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland, U.K.
Derek P
DP
Brazil
D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism*; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics / Q000378:metabolism*; D055419:Bone Morphogenetic Protein 7 / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D015398:Signal Transduction; D051898:Smad1 Protein / Q000235:genetics / Q000378:metabolism; D051902:Smad5 Protein / Q000235:genetics / Q000378:metabolism; D051904:Smad8 Protein / Q000235:genetics / Q000378:metabolism; D020349:Surface Plasmon Resonance
C525718:BMP2 protein, human; C525809:BMP4 protein, human; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D055419:Bone Morphogenetic Protein 7; C486399:GREM1 protein, human; D036341:Intercellular Signaling Peptides and Proteins; C497399:SMAD1 protein, human; C497797:SMAD5 protein, human; C107514:SMAD9 protein, human; D051898:Smad1 Protein; D051902:Smad5 Protein; D051904:Smad8 Protein