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

A number ofmutations 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 (Zc3h14(Delta ex13/Delta ex13)) leading to a truncated ZC3H14 protein. We report here that, as in the patients, Zc3h14 is not essential in mice. Utilizing these Zc3h14(Delta ex13/Delta ex13) mice, we provide the first in vivo functional characterization of ZC3H14 as a regulator of RNA poly( A) tail length. The Zc3h14(Delta ex13/Delta ex13) mice show enlarged lateral ventricles in the brain as well as impaired working memory. Proteomic analysis comparing the hippocampi of Zc3h14(+/+) and Zc3h14(Delta ex13/Delta ex13) 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 Zc3h14(Delta ex13/Delta ex13) 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.