ALC1/eIF4A1-mediated regulation of CtIP mRNA stability controls DNA end resection

Abstract

During repair of DNA double-strand breaks, resection of DNA ends influences how these lesions will be repaired. If resection is activated, the break will be channeled through homologous recombination; if not, it will be simply ligated using the non-homologous end-joining machinery. Regulation of resection relies greatly on modulating CtIP, which can be done by modifying: i) its interaction partners, ii) its post-translational modifications, or iii) its cellular levels, by regulating transcription, splicing and/or protein stability/degradation. Here, we have analyzed the role of ALC1, a chromatin remodeler previously described as an integral part of the DNA damage response, in resection. Strikingly, we found that ALC1 affects resection independently of chromatin remodeling activity or its ability to bind damaged chromatin. In fact, it cooperates with the RNA-helicase eIF4A1 to help stabilize the most abundant splicing form of CtIP mRNA. This function relies on the presence of a specific RNA sequence in the 5 0 UTR of CtIP. Therefore, we describe an additional layer of regulation of CtIP-at the level of mRNA stability through ALC1 and eIF4A1.

USP15 Enhances Re-epithelialization Through Deubiquitinating EIF4A1 During Cutaneous Wound Repair

“…Mostly, translational initiation factor family were ‘house-keeping genes’ and initiation of translation is the rate-limiting step in protein synthesis in all living cells ( Mejias-Navarro et al, 2020 ). These factors have been proven to play a vital role in wound healing, tumorigenesis, cell stemness and epithelial-mesenchymal transition, etc.…”

Recurrent chromosome reshuffling and the evolution of neo-sex chromosomes in parrots

“…Apart from the frequent chromosomal changes, the parrot genomes have a slightly higher proportion of transposable elements than other birds due to recent CR1 proliferation, and we speculate that recent CR1-psi accumulation may have provided substrates for ectopic recombination events leading to chromosomal rearrangements and the loss of at least some of the 72 conserved genes. Among the lost genes, ALC1 and PARP3 are known for their roles in genome stability and DNA double strand repair (Ahel et al 2009;Day et al 2017;Mejías-Navarro et al 2020;Boehler et al 2011;Beck et al 2014Beck et al , 2019Sellou et al 2016;Tsuda et al 2017;Zarkovic et al 2018;Belousova et al 2018;Grundy et al 2016). It has been demonstrated that deletion of ALC1 impacts chromatin relaxation which is a crucial step in responses to DNA damage (Sellou et al 2016).…”

“…and PARP3, are related to repair of DNA damage and maintenance of genome stability (Ahel et al 2009;Day et al 2017;Mejías-Navarro et al 2020;Boehler et al 2011;Beck et al 2014Beck et al , 2019Sellou et al 2016;Tsuda et al 2017;Belousova et al 2018;Zarkovic et al 2018;Grundy et al 2016). Among the 72 lost genes, 24 reside in conserved synteny blocks (collinear gene order) across bird species (Fig.…”

MRGBP, a member of the NuA4 complex, inhibits DNA double‐strand break repair

“…As described previously [24], protein extracts were prepared in 2× Laemmli buffer (4% SDS, 20% glycerol, 125 m m Tris/HCl, pH 6.8) and passed 10 times through a 0.5‐mm needle‐mounted syringe to reduce viscosity. Proteins were resolved by SDS/PAGE and transferred to low fluorescence PVDF membranes (Immobilon‐FL; Millipore, Billerica, MA, USA).…”

“…We used the same protocol previously described in [24]. Briefly, cells were fixed with cold 70% ethanol overnight, incubated with 250 μg·mL −1 RNase A (Sigma) and 10 μg·mL −1 propidium iodide (Fluka, Buchs, Switzerland) at 37 ºC for 30 min, and analyzed with a FACSCalibur (BD, Franklin Lakes, NJ, USA).…”