Periodontitis, a prevalent and chronic inflammatory disease, is intricately linked with macroautophagy/autophagy, which has a dual role in maintaining periodontal homeostasis. Despite its importance, the precise interplay between autophagy and periodontitis pathogenesis remains to be fully elucidated. In this study, our investigation revealed that the ubiquitination of RAB7A, mediated by reduced levels of the deubiquitinating enzyme USP4 (ubiquitin specific peptidase 4), disrupts normal lysosomal trafficking and autophagosome-lysosome fusion, thereby contributing significantly to periodontitis progression. Specifically, through genomic and histological analysis of clinical gingival samples, we observed a decreased RAB7A expression and impaired autophagic activity in periodontitis. This was further substantiated through experimental periodontitis mice, where RAB7A inactivation was shown to directly affect autophagy efficiency and drive periodontitis progression. Next, we explored the function of active RAB7A to promote lysosomal trafficking dynamics and autophagosome-lysosome fusion, which was inhibited by RAB7A ubiquitination in macrophages stimulated by