Odontogenic Ameloblast-associated Protein (ODAM) Mediates Junctional Epithelium Attachment to Teeth via Integrin-ODAM-Rho Guanine Nucleotide Exchange Factor 5 (ARHGEF5)-RhoA Signaling.
Bottom Line: Although odontogenic ameloblast-associated protein (ODAM) is expressed in the JE, its molecular functions remain unknown.ODAM-mediated RhoA signaling resulted in actin filament rearrangement.These results suggest that ODAM expression in the JE reflects a healthy periodontium and that JE adhesion to the tooth surface is regulated via fibronectin/laminin-integrin-ODAM-ARHGEF5-RhoA signaling.
Affiliation: From the Departments of Oral Histology/Developmental Biology and.Show MeSH
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Mentions: In our previous study, ARHGEF5 was identified as an ODAM-interacting protein by protoarray analysis (22). In immunoprecipitation (IP) assay, ODAM also showed endogenous interaction with ARHGEF5 in ALCs (Fig. 3A). To confirm whether ODAM could interact with ARHGEF5, ALCs were cotransfected with ARHGEF5and HA-tagged ODAM constructs for IP assay. The results demonstrated the interaction of ODAM with ARHGEF5 (Fig. 3B). IP with the FLAG antibody followed by blotting with the ARHEGF5 antibody indicated that amino acids 127–279 of ODAM affected the interaction between ODAM and ARHGEF5 (Fig. 3C). Pulldown assays also showed a direct interaction between these two proteins (Fig. 3D). Immunofluorescence microscopy revealed that the majority of GFP-tagged ODAM and FLAG-tagged ARHGEF5 proteins colocalized to the periphery of ALCs (Fig. 3E). Overall, these data suggest that the interaction between the C terminus of ODAM and the SH domain of ARHGEF5 occurs in the cell periphery of ameloblasts.
Affiliation: From the Departments of Oral Histology/Developmental Biology and.