Biology subjects

Gray, N. K.

Publications and source records attributed to Gray, N. K..

3 recordsLinked to original sources

bioRxiv2026

Lysine acetylation facilitates competitive recruitment of translation termination factor eRF3a by PABPC1 C-terminal domain

In eukaryotic cells, almost all mRNA transcripts are polyadenylated in the nucleus, with the poly(A)-tail being critical for their export, translation and stability. PABPC1 is a multifunctional RNA-binding protein (RBP) that binds poly(A)-tails and is a key driver of mRNA post-transcriptional regulation. It achieves this in part by interacting with a broad range of PAM2-motif containing proteins that bind the same common site within PABPC1s PABC domain but result in diverse regulatory outcomes. Regulation of this intricate network of interactions remains poorly understood but our previous studies revealed the regulatory potential of mutually-exclusive acetylation or dimethylation of a key lysine sidechain (K606). To address this, we undertook a systematic study of PAM2-motifs, identifying translation termination factor eRF3a and translation repressor PAIP2 as having a >ten-fold higher affinity for PABPC1 relative to eleven other PAM2-motif partner proteins. Acetylation of PABPC1 at K606 specifically enhances its affinity for eRF3a in vitro, and we present the crystal structure of the specifically K606 acetylated C-terminal domain of PABPC1 in complex with the PAM2 motif of eRF3a, providing structural and functional insights into how acetylation facilitates competitive eRF3a recruitment to PABPC1 and mRNA. We further demonstrate that K606 acetylation promotes PABPC1-eRF3a interaction in cells, thereby antagonising other PAM2-dependent RNA effectors. Taken together, our results show that acetylation of lysine 606 in the PABC domain can specifically modulate PABPC1 partner selectivity, providing crucial insight into how PABPC1 multifunctionality can be regulated to coordinate mRNA usage and fate in the cytoplasm.

molecular biology↗

bioRxiv2025

Mammalian PABPC4 is non-essential, but has roles in growth, post-natal survival and haematopoiesis.

Cytoplasmic poly(A)-binding proteins (PABPCs) are multifunctional RNA-binding proteins which play crucial roles in mRNA translation and stability. In mammals, two family members, PABPC1 and PABPC4 appear widely expressed, but the consequences of their loss of function in vivo remain unknown, despite PABPC4 being implicated in a variety of human diseases. We address this knowledge gap using a series of Pabpc4 knock-out mice. Unexpectedly, we reveal that mammalian PABPC4 is not essential for development, contrary to findings in non-mammalian vertebrates. However, its loss affects birth weight, post-natal growth trajectories and survival, although these were not tightly associated. Growth to adulthood was impacted in a sexually dimorphic manner. Viable Pabpc4-deficient mice allowed us to interrogate roles of Pabpc4 that may affect human health. Anaemia represents a large global health burden, and work in a red blood cell (RBC) model suggested a potential role in haemoglobin synthesis. Surprisingly in vivo, we find that Pabpc4 loss did not reduce haemoglobin levels but caused microcytic RBCs and altered RBC distribution width. Moreover, conditional genetic approaches established that this was not a red blood cell intrinsic effect. Taken together, this work provides unprecedented insights into the in vivo functions of mammalian PABPC4, and caution against inferring mammalian PABPC function from work in cell-based models and/or non-mammalian species. The generated mouse lines also form a valuable resource with which to further investigate the roles of PABPC4 in health and disease. Significance StatementRNA-binding protein (RBP)-mediated post-transcriptional regulation is essential for life and life-long health. Cytoplasmic poly(A)-binding proteins are family of RBPs that regulate multiple aspects of cytoplasmic mRNA fate. PABPC4 is an understudied family member, genetically associated with a wide range of human diseases. By creating a series of Pabpc4 knock-out mice, we surprisingly find it is not essential but is required for normal post-natal survival and growth and normal red blood cell development. Our results emphasise the importance of whole organism studies for understanding mammalian PABP function, uncovering differences between function inferred from other vertebrate species and prior cell-based work. The generated mice also provide a valuable resource for exploring its potential broad roles in human disease.

molecular biology↗

bioRxiv2021

DAZL regulates mRNA deadenylation independently of translation in germ cells

Aberrant gene expression during gametogenesis is one of the factors underlying infertility, which affects roughly 15% of couples worldwide. Deleted-in-Azoospermia-Like (DAZL), a member of the DAZ-gene family, encodes an mRNA-specific regulator of translation which is essential for gametogenesis in both sexes. In this study we show that DAZL controls gene expression in oocytes by regulating the length of the mRNA poly(A) tail, a major determinant of temporal and amplitudinal gene regulation in germ cells, in which gene expression is regulated entirely post-transcriptionally. We show that DAZL does not induce polyadenylation but that binding of DAZL efficiently inhibits mRNA deadenylation induced by oocyte maturation. We reveal that this activity depends on DAZL-mediated recruitment of poly(A)-binding protein, PABP, to the mRNA. Although DAZL also activates mRNA translation via PABP recruitment, mechanistic analysis revealed that neither translation nor translational activation are required for DAZL to stabilise the poly(A) tail, suggesting two mutually independent posttranscriptional roles for the DAZL-PABP complex. We show that recruited PABP must maintain its ability to bind RNA, leading to a model in which DAZL recruits PABP and/or stabilises PABP binding to poly(A) thereby preventing access of deadenylases. These results indicate that the role of DAZL in regulating germ-cell mRNA fate is more complex than previously thought and inform on the poorly understood links between mRNA translation and deadenylation, showing that they can be mechanistically separable.

molecular biology↗