Biology subjects

Rusha, E.

Publications and source records attributed to Rusha, E..

3 recordsLinked to original sources

bioRxiv2026

RTTN moonlights beyond the centrosome to control ribosome biogenesis and tRNA modification in human brain organoids

RTTN (rotatin) is a centrosomal protein mutated in severe malformations of cortical development, yet how its dysfunction disrupts human corticogenesis has remained unclear. Here, we show that RTTN has an unrecognized function at the core of the translation machinery. Using human telencephalic and hippocampal organoids carrying distinct RTTN alleles, together with single-cell and bulk transcriptomics, polysome profiling, and tRNA pseudouridine sequencing, we find that RTTN is enriched in cycling first-trimester neural progenitors and physically associates with ribosome-biogenesis and RNA-processing factors. RTTN mutations impair rRNA biogenesis and polysome assembly, reduce cytoplasmic ribosome density and nascent protein synthesis, and remodel the tRNA pseudouridylation landscape through both a PUS7L-dependent variable-arm signature and a broader RTTN-specific defect. These translational deficits are accompanied by prolonged mitosis, reduced entry into S-phase, and impaired interkinetic nuclear migration in mutant progenitors. Our findings redefine RTTN as a regulator of ribosome homeostasis and mRNA translation and implicate defective translational capacity as a driver of RTTN-associated microcephaly. Graphical AbstractRTTN sustains ribosome and tRNA homeostasis in human neural progenitors; its mutation disrupts mRNA translation, stalling progenitor proliferation and interkinetic nuclear migration, and driving cortical malformation and growth failure. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=151 SRC="FIGDIR/small/744412v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@16124aaorg.highwire.dtl.DTLVardef@ae23f7org.highwire.dtl.DTLVardef@bb588forg.highwire.dtl.DTLVardef@1b35028_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2024

Capture of Human Neuromesodermal and Posterior Neural Tube Axial Stem Cells

The spinal cord, nerves, and skeletal muscles arise from neuromesodermal progenitors (NMPs). We have developed a growth-factor screening strategy, utilizing ES and iPS cells, facilitating the indefinite self-renewal of two types of human axial stem cells (AxSCs), closely resembling mouse NMPs (NM-AxSCs) and posterior neural tube progenitors (N-AxSCs). Under specific regimens-- Wnt/CHIR99021, FGF2, and TGF-{beta} inhibitor SB431542 (CFS) and excluding FGF2 (CS), respectively--these AxSCs self-renew and sustain telomeres. Single cell transcriptomics and proteomics have revealed expression of posterior growth-zone and dorsoventral neural tube markers in NM-AxSCs, and correspondingly, differentiation to a wide spectrum of neural tube neurons and myocytes. N-AxSCs rapidly matured into dorsal sensory subsets and neural crest. Crucially, neither AxSC type produces teratomas, and analogous mouse NM-AxSCs integrated successfully into the neural tube and somites. Capturing of AxSCs from patient and GMP ES / iPS cells without transgenesis unveils ontogeny and promises modeling and therapy in neuropathies.

developmental biology↗

bioRxiv2022

Depletion of the RNA-binding protein PURA triggers changes in posttranscriptional gene regulation and loss of P-bodies

The RNA-binding protein PURA has been implicated in the rare, monogenetic, neurodevelopmental disorder PURA Syndrome. PURA binds both DNA and RNA and has been associated with various cellular functions. Only little is known about its main cellular roles and the molecular pathways affected upon PURA depletion. Here, we show that PURA is predominantly located in the cytoplasm, where it binds to thousands of mRNAs. Many of these transcripts change abundance in response to PURA depletion. The encoded proteins suggest a role for PURA in immune responses, mitochondrial function, autophagy and processing (P)-body activity. Intriguingly, reduced PURA levels decrease the expression of the integral P-body components LSM14A and DDX6 and strongly affect P-body formation in human cells. Furthermore, PURA knockdown results in stabilization of P-body-enriched transcripts, whereas other mRNAs decrease. Hence, reduced PURA levels, as reported in patients with PURA Syndrome, influence the formation and composition of this phase-separated RNA processing machinery. Our study proposes PURA Syndrome as a new model to study the tight connection between P-body-associated RNA regulation and neurodevelopmental disorders. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/479353v2_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@5712f9org.highwire.dtl.DTLVardef@9eb133org.highwire.dtl.DTLVardef@83b7b2org.highwire.dtl.DTLVardef@1912e5c_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗