A multifunctional protein EWS regulates the expression of Drosha and microRNAs

Abstract

, 5,6,9 EWS (Ewing's Sarcoma) gene encodes an RNA/DNA-binding protein that is ubiquitously expressed and involved in various cellular processes. EWS deficiency leads to impaired development and early senescence through unknown mechanisms. We found that EWS regulates the expression of Drosha and microRNAs (miRNAs). EWS deficiency resulted in increased expression of Drosha, a well-known microprocessor, and increased levels of miR-29b and miR-18b. Importantly, miR-29b and miR-18b were directly involved in the post-transcriptional regulation of collagen IV alpha 1 (Col4a1) and connective tissue growth factor (CTGF) in EWS knock-out (KO) mouse embryonic fibroblast cells. The upregulation of Drosha, miR-29b and miR-18b and the sequential downregulation of Col4a1 and CTGF contributed to the deregulation of dermal development in EWS KO mice. Otherwise, knockdown of Drosha rescued miRNA-dependent downregulation of Col4a1 and CTGF proteins. Taken together, our data indicate that EWS is involved in post-transcriptional regulation of Col4a1 and CTGF via a Drosha-miRNA-dependent pathway. This finding suggests that EWS has a novel role in dermal morphogenesis through the modulation of miRNA biogenesis. 1 EWS also interacts with subunits of transcription factor II D, CREB-binding protein (CBP) and RNA polymerase II complexes, suggesting a role in basic transcription.2 Subsequent studies have shown that EWS acts as a transcriptional activator for BRN3A, HNF3, and OCT4 in a cell-type-and promoter-specific manner.3-5 Interestingly, EWS gene is frequently rearranged by chromosomal translocations in several cancers, leading to its fusion with many transcription factors including FLI1, ATF1, and WT1. The resulting chimeric fusion proteins, such as EWS-FLI1, EWS-ATF1, and EWS-WT1, function as aberrant transcription factors that drive proliferation, survival, and transformation.

EWS–WT1 Oncoprotein Activates Neuronal Reprogramming Factor ASCL1 and Promotes Neural Differentiation

“…EWS encodes an RNA/ssDNA-binding protein that plays multiple roles in diverse cellular processes, such as maturation of pre-B lymphocytes, meiosis, hypersensitivity to DNA damage, prevention of premature senescence of fibroblasts (6), and hematopoietic stem cells (7), mitosis (8), cell-fate determination of classical brown fat (9), regulation of microRNAs (10), and regulation of genotoxic-induced alternative splicing (11,12). The NTD of EWS contains multiple degenerate repeats of the SYGQQS motif that functions as a potent transcriptional activation domain (13,14).…”

Inactivation of EWS reduces PGC-1α protein stability and mitochondrial homeostasis

“…EWS is a multifunctional protein with multiple roles in diverse cellular processes, such as maturation of pre B lymphocytes, meiosis, hypersensitivity to DNA damage, prevention of premature senescence of fibroblasts (11) and hematopoietic stem cells (12), mitosis (13), DNA damage-induced alternative splicing (9, 10), cell-fate determination of classical brown fat (8) and regulation of microRNAs (15). This study ascribes a new function to EWS in mitochondrial homeostasis and cellular energy metabolism.…”

“…Animal studies with genetic ablation of Ews have revealed a surprisingly diverse role of EWS in various cellular processes such as pre-B lymphocyte development, meiosis, mitosis and prevention of premature cellular senescence in fibroblasts and hematopoietic stem cells (11)(12)(13). Recently, it was shown that EWS is required for determining embryonic brown fat cell fate during development (8), for in vitro white fat differentiation (14), and in the regulation of microRNAs (15).…”

Uvragtargeting byMir125aandMir351modulates autophagy associated withEwsr1deficiency

“…DROSHA is a miRNA processor and plays a pivotal role in miRNA maturation from primiRNA to pre-miRNA. 33 Because DROSHA is increased by EWSR1 deficiency, 34 we hypothesized that UVRAG levels may be modulated by a DROSHA-miRNAs-dependent pathway. We performed miRNA microarray analyses and identified that Mir125a and Mir351 are significantly increased in ewsr1…”

“…34 Preabsorption with excess target proteins, omission of the primary antibody, and omission of secondary antibodiy were performed to determine the amount of background generated from the detection assay.…”