The MLL/Setd1b methyltransferase is required for the Spemann's organizer gene activation in Xenopus

Postnatal expression of the lysine methyltransferase SETD1B is essential for learning and the regulation of neuron-enriched genes

In mammals, histone 3 lysine 4 methylation (H3K4me) is mediated by six different lysine methyltransferases. Among these enzymes, SETD1B (SET domain containing 1b) has been linked to syndromic intellectual disability in human subjects, but its role in the mammalian postnatal brain has not been studied yet. Here, we employ mice deficient for Setd1b in excitatory neurons of the postnatal forebrain, and combine neuron-specific ChIP-seq and RNA-seq approaches to elucidate its role in neuronal gene expression. We observe that Setd1b controls the expression of a set of genes with a broad H3K4me3 peak at their promoters, enriched for neuron-specific genes linked to learning and memory function. Comparative analyses in mice with conditional deletion of Kmt2a and Kmt2b histone methyltransferases show that SETD1B plays a more pronounced and potent role in regulating such genes. Moreover, postnatal loss of Setd1b leads to severe learning impairment, suggesting that SETD1B-dependent regulation of H3K4me levels in postnatal neurons is critical for cognitive function.

High‑level SETD1B gene expression is associated with unfavorable prognosis in hepatocellular carcinoma

The SET domain-containing 1B (SETD1B) gene is involved in multiple biological processes, including tumor development and progression. However, the role of SETD1B in hepatocellular carcinoma (HCC) is largely unexplored. The present study, examined the expression of SETD1B in patients with HCC and assessed its clinical significance. Reverse transcriptase quantitative polymerase chain reaction and western blot analysis results revealed that the expression levels of SETD1B mRNA and protein were significantly increased in HCC tumor tissues compared with the adjacent normal tissues. In addition, an analysis of the patient clinical factors indicated that increased levels of SETD1B expression were associated with tumor size, clinical stage and liver cirrhosis. Patients with HCC with decreased levels of SETD1B expression exhibited longer survival times compared with those with increased levels of SETD1B expression. In addition, Cox's regression analysis results implied that the upregulation of SETD1B was an independent prognostic marker in patients with HCC. Taken together, the results demonstrated that SETD1B is essential in the progression of HCC and may be used as a potential prognostic marker and therapeutic target in HCC.

The RNF146 E3 ubiquitin ligase is required for the control of Wnt signaling and body pattern formation in Xenopus

The RING finger protein Rnf146 encodes an E3 ubiquitin ligase capable of targeting poly-ADP-ribosylated substrates for proteasomal degradation. Rnf146 has been identified as a critical regulator of Axin1 and thus of Wnt/β-catenin signaling. However its physiological significance in vertebrate embryonic development remains to be demonstrated. In this study, we take advantages of early Xenopus embryos to demonstrate that Rnf146 is essential for embryonic pattern formation. Depletion of zygotic Rnf146 using a translation blocking morpholino oligo (MO) results in anteriorized development and increased expression the anterior marker gene Otx2, consistent the notion that Rnf146 is a positive regulator of Wnt/β-catenin signaling through negatively regulating Axin1 expression. This notion is further supported by examination of the role of maternal Rnf146 in the context of Spemann organizer formation and dorsal axis development. Depletion of maternal Rnf146 using an antisense oligodeoxynucleic acid (ODN) leads to ventralized development and diminished expression of organizer genes. Together, we have provided evidence for the first time that Rnf146 is a critical regulator of embryonic pattern formation in vertebrates.