Structural Insight into the DNA Binding Function of Transcription Factor ERF

De novo mutations in the BMP signaling pathway in lambdoid craniosynostosis

Lambdoid craniosynostosis (CS) is a congenital anomaly resulting from premature fusion of the cranial suture between the parietal and occipital bones. Predominantly sporadic, it is the rarest form of CS and its genetic etiology is largely unexplored. Exome sequencing of 25 kindreds, including 18 parent-offspring trios with sporadic lambdoid CS, revealed a marked excess of damaging (predominantly missense) de novo mutations that account for ~ 40% of sporadic cases. These mutations clustered in the BMP signaling cascade (P = 1.6 × 10^-7), including mutations in genes encoding BMP receptors (ACVRL1 and ACVR2A), transcription factors (SOX11, FOXO1) and a transcriptional co-repressor (IFRD1), none of which have been implicated in other forms of CS. These missense mutations are at residues critical for substrate or target sequence recognition and many are inferred to cause genetic gain-of-function. Additionally, mutations in transcription factor NFIX were implicated in syndromic craniosynostosis affecting diverse sutures. Single cell RNA sequencing analysis of the mouse lambdoid suture identified enrichment of mutations in osteoblast precursors (P = 1.6 × 10^-6), implicating perturbations in the balance between proliferation and differentiation of osteoprogenitor cells in lambdoid CS. The results contribute to the growing knowledge of the genetics of CS, have implications for genetic counseling, and further elucidate the molecular etiology of premature suture fusion.

The CIC-ERF co-deletion underlies fusion-independent activation of ETS family member, ETV1, to drive prostate cancer progression

Human prostate cancer can result from chromosomal rearrangements that lead to aberrant ETS gene expression. The mechanisms that lead to fusion-independent ETS factor upregulation and prostate oncogenesis remain relatively unknown. Here, we show that two neighboring transcription factors, Capicua (CIC) and ETS2 repressor factor (ERF), which are co-deleted in human prostate tumors can drive prostate oncogenesis. Concurrent CIC and ERF loss commonly occur through focal genomic deletions at chromosome 19q13.2. Mechanistically, CIC and ERF co-bind the proximal regulatory element and mutually repress the ETS transcription factor, ETV1. Targeting ETV1 in CIC and ERF-deficient prostate cancer limits tumor growth. Thus, we have uncovered a fusion-independent mode of ETS transcriptional activation defined by concurrent loss of CIC and ERF.

Intrafamilial variability in six family members with ERF-related craniosynostosis syndrome type 4

ERF-related craniosynostosis syndrome type 4 (CRS4, OMIM #600775) is a rare autosomal dominant malformation syndrome, caused by pathogenic variants in the ERF gene and characterized by craniosynostosis, developmental delay, and dysmorphic features such as hypertelorism, exophthalmos, depressed nasal bridge, and retrognathia. So far, there are mostly individual reports and only a few descriptions of families with more than two affected patients, allowing statements about the penetrance of a certain variant and its variability only to a limited extent. In this study, we report an in-depth analysis of the clinical course of six family members from three generations with the novel heterozygous nonsense variant c.286A>T (p.Lys96*) in the ERF gene. At the time of examination, all of the six patients showed mild dysmorphic features and brachydactyly, five were overweight/obese and had delayed speech development, and four were short in stature. Hyperactivity, a short concentration span and a history of learning difficulties were found in half of the affected family members. To this day, none of the patients developed increased intracranial hypertension that would require surgical intervention. This work provides further information on the expressive variability of an ERF variant in six members of one family and focuses on the need for close neuropediatric surveillance.