Title :
Obif , a
Transmembrane Protein , Is Required for Bone Mineralization and Spermatogenesis in Mice
Abstract :
- BACKGROUND: Various kinds of transmembrane and secreted proteins play pivotal roles in development through cell-cell communication
- We previously reported that Obif ( Osteoblast induction factor , Tmem119 ), encoding a single transmembrane protein , is expressed in differentiating osteoblasts, and that Obif-/- mice exhibit significantly reduced bone volume in the femur
- In the current study, we characterized the Obif protein and further investigated the biological phenotypes of a variety of tissues in Obif-/- mice
- RESULTS: First, we found that O-glycosylation of the Obif protein occurs at serine residue 36 in the Obif extracellular domain
- Next, we observed that Obif-/- mice exhibit bone dysplasia in association with significantly increased osteoid volume per osteoid surface (OV/OS) and osteoid maturation time (Omt), and significantly decreased mineral ap position rate (MAR) and bone formation rate per bone surface (BFR/BS)
- In addition, we observed that Obif-/- mice show a significant decrease in testis weight as well as in sperm number
- By histological analysis, we found that Obif is expressed in spermatocytes and spermatids in the developing testis and that spermatogenesis is halted at the round spermatid stage in the Obif-/- testis that lacks sperm
- However, the number of litters fathered by male mice was slightly reduced in Obif-/- mice compared with wild-type mice, although this was not statistically significant
- CONCLUSIONS: Our results, taken together with previous observations, indicate that Obif is a type Ia transmembrane protein whose N-terminal region is O-glycosylated
- In addition, we found that Obif is required for normal bone mineralization and late testicular differentiation in vivo
- These findings suggest that Obif plays essential roles in the development of multiple tissues
Output (sent_index, trigger,
protein,
sugar,
site):
- 4. O-glycosylation, , Obif protein, -, serine residue 36
- 9. O-glycosylated, , -, -, region
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):