Cloning and characterization of the human SH3BP2 promoter

Abstract

SH3BP2 activating mutations lead to a unique clinical condition in which patients develop symmetrical bone resorptive lesions of the jaw, a condition termed cherubism. Due to this specific temporal sequence and location of bone resorption, we investigated the transcriptional regulation of SH3BP2 expression. Analyses of 5′- and 3′-serial promoter deletions defined the core promoter/regulatory elements, including two repressor sites (from −1,200 to −1,000 and from +86 to +115, respectively) and two activator sites (a PARP1 binding site from −44 to −21 and a second activator site from +57 to +86). We identified that PARP1 binds to DNA from −44 to −21 by Streptavidin-biotin purification and confirmed this binding by electrophoretic mobility shift assay (EMSA). Mutagenesis of the PARP1 binding site on the SH3BP2 promoter showed that this binding site is essential for SH3BP2 expression. EMSA and chromatin immunoprecipitation (ChIP) assays confirmed that PARP1 was able to bind to the SH3BP2 promoter in vitro and in vivo. Indeed, knockout of Parp1 in mice BMMs reduced expression of SH3BP2. These results demonstrate that PARP1 regulates expression of SH3BP2.

DNA methylation profile discriminates sporadic giant cell granulomas of the jaws and cherubism from their giant cell‐rich histological mimics

“…Although SH3BP2 functions have not been entirely elucidated, plausible interactions of this protein with MAPK/ERK pathway have been raised by others [ 1 ], but such interactions remain untested. The SH3BP2 gene contains C/G‐rich regions and more than 42 CpG islands which are targets for gene regulation by DNA methylation, which likely makes it susceptible to regulation by epigenetic mechanisms [ 35 ]. Interestingly, the DNA methylation analysis shows that cherubism samples cluster together with central GCG, highlighting that the similarities extend from microscopic to the epigenetic level, despite genetic differences.…”

Clinical and genetic analysis of patients with cherubism

“…A subsequent study demonstrated that knock‐in mice for SH3BP2 would alter bone quality, reduce osteoblast function, and contribute to bone resorption (Wang et al., ), demonstrating the importance of this gene in the osteoclastogenesis. SH3BP2 product was initially identified as a c‐Abl‐binding protein in mice and humans, and despite its presence in most of the human cells, cherubism lesions are intriguingly restricted to the jaws, also carrying a temporal clinical manifestation (Fan et al., ; Reichenberger et al., ). Different mutations affecting SH3BP2 have been described in literature, and all alterations found in this study (R415Q, P418T, and P418H) had already been described before, all of them involving exon 9 (Sangu et al., ; Sekerci et al., ).…”

Tankyrase (PARP5) Inhibition Induces Bone Loss through Accumulation of Its Substrate SH3BP2

“…Regarding the effect of PARP1 on bone, SH3BP2 might act as a modifier of PARP1-mediated bone homeostasis, not just tankyrase-mediated bone homeostasis. PARP1 is reported to bind the human SH3BP2 promoter and regulates SH3BP2 gene expression [87]. In PARP1-deficient murine bone marrow-derived macrophages, Sh3bp2 promoter activity and SH3BP2 protein expression are significantly suppressed [87].…”

“…PARP1 is reported to bind the human SH3BP2 promoter and regulates SH3BP2 gene expression [87]. In PARP1-deficient murine bone marrow-derived macrophages, Sh3bp2 promoter activity and SH3BP2 protein expression are significantly suppressed [87]. Though further research will be required to determine whether SH3BP2 is involved in PARP1-mediated bone homeostasis, SH3BP2 might be involved in osteoclast differentiation through two different mechanisms, transcriptional regulation by PARP1 and post-translational regulation by tankyrase.…”