Reduced dosage of ERF causes complex craniosynostosis in humans and mice and links ERK1/2 signaling to regulation of osteogenesis

Abstract

The extracellular signal-related kinases 1 and 2 (ERK1/2) are key proteins mediating mitogen-activated protein kinase signaling downstream of RAS: phosphorylation of ERK1/2 leads to nuclear uptake and modulation of multiple targets. Here, we show that reduced dosage of ERF, which encodes an inhibitory ETS transcription factor directly bound by ERK1/2 (refs. 2,3,4,5,6,7), causes complex craniosynostosis (premature fusion of the cranial sutures) in humans and mice. Features of this newly recognized clinical disorder include multiple-suture synostosis, craniofacial dysmorphism, Chiari malformation and language delay. Mice with functional Erf levels reduced to ∼30% of normal exhibit postnatal multiple-suture synostosis; by contrast, embryonic calvarial development appears mildly delayed. Using chromatin immunoprecipitation in mouse embryonic fibroblasts and high-throughput sequencing, we find that ERF binds preferentially to elements away from promoters that contain RUNX or AP-1 motifs. This work identifies ERF as a novel regulator of osteogenic stimulation by RAS-ERK signaling, potentially by competing with activating ETS factors in multifactor transcriptional complexes.

Expanding the mutation spectrum in 182 Spanish probands with craniosynostosis: identification and characterization of novel TCF12 variants

“…In contrast to the original report of a significant number of ERF mutations in multiple-suture craniosynostosis, we failed to detect a mutation in this gene. This study suggests that the frequency of ERF mutations may be lower than previously suggested (2-3%), 11 but analysis of larger cohorts are required to determine this further.…”

“…29 During the course of the project, two novel craniosynostosis genes were identified; TCF12 (Sharma et al 9 ) and ERF. 11 We subsequently screened both genes in the 72 patients, which remained genetically undiagnosed after the cascade screening. Five patients were found to have a TCF12 variant, accounting for 2.7% of the total cohort.…”

“…Mutations in ERF were identified in 12/411 patients with a complex form of craniosynostosis. 11 Phenotypic variability in craniosynostosis makes the clinical diagnosis difficult; thus, genetic testing can support or aid the clinical diagnosis and improve genetic counselling in these families. Evidence also suggests that molecular diagnosis can help to define the treatment or surgery necessary in the short to medium term and predict the clinical evolution.…”

De novo mutations in inhibitors of Wnt, BMP, and Ras/ERK signaling pathways in non-syndromic midline craniosynostosis

“…LOF variants in ERF cause multisuture craniosynostosis with variable midface hypoplasia (29). To our knowledge, no cases of isolated metopic NSC have previously been described in conjunction with LOF mutation in ERF.…”

Fibroblast growth factor signaling in skeletal development and disease

“…In several mouse models, Apert FGFR2(S252W) mutations activate ERK1/2, p38 MAPK, AKT, β-catenin, and PLCγ in osteogenic cells, which may contribute to premature cranial ossification (Chen et al 2003;Kim et al 2003;Shukla et al 2007;Yin et al 2008;Wang et al 2010;Suzuki et al 2012). Interestingly, reduced dosage of ERF, an inhibitory ETS transcription factor directly bound by ERK1/2 signaling, was found to cause craniosynostosis in humans and mice, implying a role of ERF downstream from ERK signaling in cranial suture ossification (Twigg et al 2013). In human craniosynostosis, increased osteoblast gene expression and cranial osteogenesis induced by Apert FGFR2(S252W) mutation are related to PLCγ and PKCα activation (Lemonnier et al 2001b).…”