Transmembrane glycoprotein NMB is a protein that in humans is encoded by the GPNMB gene. The mouse and rat orthologues of GPNMB are known as DC-HIL and Osteoactivin (OA), respectively. Two transcript variants encoding 560 and 572 amino acid isoforms have been characterized for this gene in humans. GPNMB is a type I transmembrane glycoprotein which shows homology to the pmel17 precursor, a melanocyte-specific protein.
GPNMB has been reported to be expressed in various cell types, including: melanocytes, osteoclasts, osteoblasts, dendritic cells, and it is overexpressed in various cancer types. In melanocytic cells and osteoclasts the GPNMB gene is transcritionally regulated by Microphthalmia-associated transcription factor. In osteoblast progenitor cells, Osteoactivin works as a positive regulator of osteoblast differentiation during later stages of matrix maturation and mineralization that is mediated at least in part by BMP-2 in a SMAD1 dependent manner to promote osteoblast differentiation. In addition, using a rat fracture model, Osteoactivin (OA) enhances the repairing process in bone fracture, demonstrated by its high expression during chondrogenesis (soft callus) and osteogenesis (hard callus) compared to the intact femurs that is why Osteoactivin (OA) could be a novel therapeutic agent used to treat generalized osteoporosis or localized osteopenia during fracture repair by stimulating bone growth and regeneration. Similarly, Osteoactivin expression increases during osteoclast differentiation and it is functionally implicated in this process, possibly by promoting the fusion of osteoclast progenitor cells.
GPNMB involved in several pathways and played different roles in them. We selected most pathways GPNMB participated on our site, such as , which may be useful for your reference. Also, other proteins which involved in the same pathway with GPNMB were listed below. Creative BioMart supplied nearly all the proteins listed, you can search them on our site.
Pathway Name
Pathway Related Protein
GPNMB has several biochemical functions, for example, heparin binding, integrin binding. Some of the functions are cooperated with other proteins, some of the functions could acted by GPNMB itself. We selected most functions GPNMB had, and list some proteins which have the same functions with GPNMB. You can find most of the proteins on our site.
GPNMB has direct interactions with proteins and molecules. Those interactions were detected by several methods such as yeast two hybrid, co-IP, pull-down and so on. We selected proteins and molecules interacted with GPNMB here. Most of them are supplied by our site. Hope this information will be useful for your research of GPNMB.
SMAD4
Torres, C; Linares, A; et al. The Potential Role of the Glycoprotein Osteoactivin/Glycoprotein Nonmetastatic Melanoma Protein B in Pancreatic Cancer. PANCREAS 44:302-310(2015).
