RSL24D1 sustains steady-state ribosome biogenesis and pluripotency translational programs in embryonic stem cells

Abstract

Embryonic stem cell (ESC) fate decisions are regulated by a complex molecular circuitry that requires tight and coordinated gene expression regulations at multiple levels from chromatin organization to mRNA processing. Recently, ribosome biogenesis and translation have emerged as key regulatory pathways that efficiently control stem cell homeostasis. However, the molecular mechanisms underlying the regulation of these pathways remain largely unknown to date. Here, we analyzed the expression of over 300 genes involved in ribosome biogenesis in mouse ESCs and identified RSL24D1 as the most differentially expressed between self-renewing and differentiated ESCs. RSL24D1 is highly expressed in multiple mouse pluripotent stem cell models and its expression profile is conserved in human ESCs. RSL24D1 is associated with nuclear pre-ribosomes and is required for the maturation and the synthesis of 60S subunits in mouse ESCs. Interestingly, RSL24D1 depletion significantly impairs global translation, particularly of key pluripotency factors, including POU5F1 and NANOG, as well as components of the polycomb repressive complex 2 (PRC2). Consistently, RSL24D1 is required for mouse ESC self-renewal and proliferation. Taken together, we show that RSL24D1-dependant ribosome biogenesis is required to both sustain the expression of pluripotent transcriptional programs and silence developmental programs, which concertedly dictate ESC homeostasis.

Human pre-60S assembly factors link rRNA transcription to pre-rRNA processing

“…Here, we report the functional analysis of the putative ribosome biogenesis assembly factor RSL24D1. This protein was previously identified to be important for rRNA synthesis (Tafforeau et al 2013; Durand et al 2021), and consistent with this report, we demonstrate that RNAi mediated depletion of RSL24D1 specifically inhibits the late pre-rRNA processing steps required for 60S subunit formation. Moreover, repression of this pathway by RSL24D1 depletion leads to global reduction in mRNA translation.…”

“…Similarly, there are several diseases caused by mutations in ribosomal proteins of the LSU including Diamond-Blackfan anemia ( RPL5; RPL11; RPL27 ) (Boria et al 2010) and X-linked intellectual disability ( RPL10 ) (Brooks et al 2014). Intriguingly, RSL24D1 was recently reported to be required for murine embryonic stem cell proliferation (Durand et al 2021). The prevalence of disorders arising from mutations in genes encoding ribosomal proteins and assembly factors of the large subunit highlight the importance of faithful subunit processing for the steady production of ribosomes to maintain cellular homeostasis.…”

“…RSL24D1 functions in the processing of pre-28S rRNA RSL24D1 was identified in a previous targeted RNAi depletion screen as a factor potentially involved in LSU processing in HeLa cells and 60S biogenesis in mouse embryonic stem cells (Tafforeau et al 2013;Durand et al 2021). Moreover, the RSL24D1 yeast ortholog, Rlp24, has been shown to be important for large subunit pre-rRNA processing (Kappel et al 2012).…”

Human pre-60S assembly factors link rRNA transcription to pre-rRNA processing

“…Here, we report the functional analysis of the putative RiBi assembly factor RSL24D1. This protein was previously identified to be important for 60S biogenesis (Durand et al 2021;Dorner et al 2022), and consistent with these reports, we demonstrate that RNAi mediated depletion of RSL24D1 specifically inhibits the late pre-rRNA processing steps required for 60S subunit formation. Moreover, repression of this pathway by RSL24D1 depletion leads to a global reduction in mRNA translation.…”

“…RSL24D1 was identified in a previous targeted RNAi depletion screen as a factor potentially involved in LSU processing and assembly in HeLa cells and 60S biogenesis in mouse embryonic stem cells (Durand et al 2021;Dorner et al 2022). Moreover, the RSL24D1 yeast ortholog, Rlp24, has been shown to be important for large subunit pre-rRNA processing (Saveanu et al 2003).…”