The RANK IVVY Motif-regulated Genes in Osteoclastogenesis

By carrying out a systematic structure/function study of the RANK cytoplasmic domain, we previously identified a specific 4-a.a. RANK motif (IVVY535-538) which plays a critical role in osteoclastogenesis by mediating commitment of macrophages to the osteoclast lineage. We have recently validated the role of this IVVY motif in osteoclastogenesis in vivo by generating knockin (KI) mice bearing inactivating mutations in the RANK IVVY motif. This microarray experiment was performed to determine whether the IVVY motif is involved in regulating gene expression in osteoclastogenesis. We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. Bone marrow macrophages isolated from wild-type (WT) or knockin (KI) mice were plated in 60-mm tissue culture dishes and treated with M-CSF (44ng/ml) and RANKL (100ng/ml) for 24 hours. Each genotype has three triplicates. Total RNA was isolated for microarray analysis using mouse chips (type 430.2.0) at the Microarray Shared Facility at the University of Alabama at Birmingham.