Association of human DNA helicase RecQ5β with RNA polymerase II and its possible role in transcription

Abstract

Although RecQ5beta is a ssDNA (single-stranded DNA)-stimulated ATPase and an ATP-dependent DNA helicase with strand-annealing activities, its cellular function remains to be explored. In the present paper, we used immunopurification and MS-based analyses to show that human DNA helicase RecQ5beta is associated with at least four RNAP II (RNA polymerase II) subunits. RecQ5beta was also present in complexes immunoprecipitated using three different antibodies against the large subunit of RNAP II, or in complexes immunoprecipitated using an anti-FLAG antibody against either FLAG-RNAP II 33 kDa subunit or FLAG-Pin1. Different regions of the non-helicase domain of the RecQ5beta molecule were associated with hypophosphorylated and hyperphosphorylated forms of the RNAP II large subunit independently of DNA and RNA. RecQ5beta was also found in nuclear chromatin fractions and associated with the coding regions of the LDL (low-density lipoprotein) receptor and beta-actin genes. Knockdown of the RecQ5beta transcript increased the transcription of those genes. The results of the present study suggest that RecQ5beta has suppressive roles in events associated with RNAP II-dependent transcription.

RECQ5-dependent SUMOylation of DNA topoisomerase I prevents transcription-associated genome instability

“…3e and Supplementary Fig. 7), is important for providing resistance to both transcription-and TOP1-induced genome instability [13][14][15]17 . Interestingly, we found that similar to SRSF1 and PIAS1 knockdown, RECQ5 depletion also abolished TOP1 K391/K436 SUMOylation, and this defect is specific to RECQ5 but not other RECQ family DNA helicases, such as BLM (Fig.…”

“…Human RECQ5, a member of the highly conserved RECQ family of DNA helicases and a tumour suppressor 12 , is a stable RNA polymerase II (RNAPII)-interacting protein in vivo 13,14 . RECQ5 is important for preventing both transcription-associated DSBs and DSBs induced by TOP1 poisons, such as camptothecin (CPT) [15][16][17] .…”

Friend of Prmt1, FOP is a Novel Component of the Nuclear SMN Complex Isolated Using Biotin Affinity Purification

“…Pulled-down proteins were separated on a gel by SDS-PAGE; the gel was cut into some pieces, each of which was subjected to in-gel digestion with trypsin [30], and the resulting peptides were analyzed using a nanoflow LC-MS/MS system with qua-drupole-time-of-flight 2 hybrid mass spectrometer (Q-Tof2, Micromass, Wythenshawe, UK) as described [31,32]. The peptide mixture was applied to a Mightysil-RP-18 (3 µm particle, Kanto Chemical, Osaka, Japan) fritless column (45 mm×0.150 mm i.d.)…”

Erratum to: Structure and Mechanisms of SF1 DNA Helicases

“…RNA polymerases that are involved in the elongation of RNA transcripts have been considered as helicases that unwind the dsDNA to expose the ssDNA strand that serves as the template for RNA synthesis [2]. Helicases thus play a role in most transcriptional processes including activation (TFIIH), initiation (TFIIH, SNF2), maintenance (SW1), DNA repair (TFIIH, ERCC6/RAD26), and termination (Factor 2, Rho) [49, [66][67][68][69][70][71][72].…”