The RNA-binding protein, ZC3H14, is required for proper poly(A) tail length control, expression of synaptic proteins, and brain function in mice

Abstract

A number of mutations in genes that encode ubiquitously expressed RNA-binding proteins cause tissue specific disease. Many of these diseases are neurological in nature revealing critical roles for this class of proteins in the brain. We recently identified mutations in a gene that encodes a ubiquitously expressed polyadenosine RNA-binding protein, ZC3H14 (Zinc finger CysCysCysHis domain-containing protein 14), that cause a nonsyndromic, autosomal recessive form of intellectual disability. This finding reveals the molecular basis for disease and provides evidence that ZC3H14 is essential for proper brain function. To investigate the role of ZC3H14 in the mammalian brain, we generated a mouse in which the first common exon of the ZC3H14 gene, exon 13 is removed (Zc3h14Δex13/Δex13) leading to a truncated ZC3H14 protein. We report here that, as in the patients, Zc3h14 is not essential in mice. Utilizing these Zc3h14Δex13/Δex13mice, we provide the first in vivo functional characterization of ZC3H14 as a regulator of RNA poly(A) tail length. The Zc3h14Δex13/Δex13 mice show enlarged lateral ventricles in the brain as well as impaired working memory. Proteomic analysis comparing the hippocampi of Zc3h14+/+ and Zc3h14Δex13/Δex13 mice reveals dysregulation of several pathways that are important for proper brain function and thus sheds light onto which pathways are most affected by the loss of ZC3H14. Among the proteins increased in the hippocampi of Zc3h14Δex13/Δex13 mice compared to control are key synaptic proteins including CaMK2a. This newly generated mouse serves as a tool to study the function of ZC3H14 in vivo.

The Conserved, Disease-Associated RNA Binding Protein dNab2 Interacts with the Fragile X Protein Ortholog in Drosophila Neurons

“…Recovery of THOC1, a nuclear RBP (Li et al, 2005), in the nuclear fraction confirms that biochemical evidence of cytoplasmic ZC3H14 is not a non-specific pattern common to all RBPs. Anti-ZC3H14 specificity was confirmed with lysates generated from ZC3H14 Δ ex13 /Δ ex13 knockout mouse brains (Rha et al, 2017). …”

“…Darnell et al, 2011). Intriguingly, the FMRP-target mRNA CamK11a mRNA is enriched in anti-ZC3H14 precipitates and CaMKIIa levels increase in the hippocampus of Zc3h14 Δ 13 /Δ 13 knockout mice compared to control mice (Rha et al, 2017), raising the possibility that Drosophila and vertebrate CaMKII mRNAs are conserved targets of dNab2/ZC3H14. Intriguingly, the FMRP-related protein Fxr1 (Morales et al, 2002; Stackpole et al, 2014) co-precipitates with the zinc-finger domain of ZC3H14 (Hu and Gao, 2014), suggesting that ZC3H14 may interact with FMRP family members in a manner analogous to dNab2 and dFMRP.…”

Reanalysis of exome sequencing data of intellectual disability samples: Yields and benefits

“…Recently phenotypic characterization of Zc3h14 knockout mouse supports that Zc3h14 is required for proper brain function in mice and also showed that Zc3h14 plays a conserved role in poly(A) tail length control within the hippocampus. Thus ZC3H14 might regulate the expression of proteins critical for brain function . Previously, two different homozygous pathogenic variants were identified in six males from two unrelated consanguineous Iranian families with autosomal recessive mental retardation (OMIM 617125) .…”

“…Thus ZC3H14 might regulate the expression of proteins critical for brain function. 33 Previously, two different homozygous pathogenic variants were identified in six males from two unrelated consanguineous Iranian families with autosomal recessive mental retardation (OMIM 617125). 32 It is interesting that no other reports implicated ZC3H14 in non-syndromic ID although many databases indicate it is intolerant to loss of function mutations.…”

Structure–function relationships in the Nab2 polyadenosine‐RNA binding Zn finger protein family

“…This hypothesis is supported by the physical and genetic interactions seen between Nab2 and the nuclear exosome catalytic subunit, Rrp6, which has been shown to restrict the length of poly(A) tails . Furthermore, both recombinant Sc Nab2 and Sp Nab2 can protect poly(A) RNA from degradation by the RNA exosome in vitro . Critically, in the absence of nuclear Nab2, nuclear mRNA is rapidly degraded by the RNA exosome .…”