This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Bone Morphogenetic Proteins (BMPs), a subset of the Transforming Growth Factor-Beta superfamily, are involved in multiple cellular processes, including differentiation, patterning, and cell-fate determination. Signaling is induced when the BMP ligand binds to the extracellular domain of one type of receptor, enabling binding of a second type of receptor, resulting in the phosphorylation of the intracellular domain of the type I receptor. One newly identified ligand, BMP-9, has been shown to be involved in cholinergic differentiation and glucose homeostasis. We have recently collected diffraction data on crystals of BMP-9 of moderate quality at beam line 5.2.1 of the Advanced Light Source. We seek to obtain higher quality data and to extend the resolution for the BMP-9 structure. We are currently performing binding studies with the intent to crystallize BMP-9 with one of several receptor extracellular domains available to us in an effort to better characterize the interactions among binding partners of this important family of proteins.