Biophysical Society Conference | Estes Park 2023

Membrane Budding and Fusion

Poster Abstracts

42-POS Board 14 THE ROLE OF RUFY4 IN REGULATING BONE-RESORBING FUNCTION OF OSTEOCLASTS

Minhee Kim 1 ; Soo Young Lee 1 ; 1 Ewha Womans Univeristy, Life Science, Seoul, South Korea

Objective: Bone remodeling, an important process for maintaining bone homeostasis, involves the coordinated activities of osteoblasts and osteoclasts. In this study, we investigated the function of the endo-lysosomal protein RUN and FYVE domain containing 4 (RUFY4) in osteoclasts, which are bone-resorbing cells.Methods: We generated Rufy4-deficient mice by CRISPR/Cas9-mediated gene deletion and analyzed the expression of autophagy-related genes in osteoclasts derived from these mice. In addition, we examined the expression of endosomal and lysosomal markers as well as bone resorption function of osteoclasts.Results: In contrast to previous findings in dendritic cells, Rufy4 did not appear to affect autophagy gene expression in osteoclasts. However, deletion of the RUN or FYVE domains of Rufy4 significantly impaired the bone resorption function of osteoclasts. These observations indicate that Rufy4 plays an important regulatory role in osteoclast bone resorption function that is distinct from autophagy. Conclusions: Our study reveals a novel role for Rufy4 in the regulation of osteoclast bone resorption, apart from its effect on osteoclast autophagy response.

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