• An alternative pathway for membrane protein biogenesis at the endoplasmic reticulum

      O’Keefe, Sarah; orcid: 0000-0002-1744-0198; email: sarah.okeefe@manchester.ac.uk; Zong, Guanghui; orcid: 0000-0002-7335-039X; Duah, Kwabena B.; Andrews, Lauren E.; Shi, Wei Q.; orcid: 0000-0001-5453-1753; High, Stephen; orcid: 0000-0002-4532-8152; email: stephen.high@manchester.ac.uk (Nature Publishing Group UK, 2021-07-01)
      Abstract: The heterotrimeric Sec61 complex is a major site for the biogenesis of transmembrane proteins (TMPs), accepting nascent TMP precursors that are targeted to the endoplasmic reticulum (ER) by the signal recognition particle (SRP). Unlike most single-spanning membrane proteins, the integration of type III TMPs is completely resistant to small molecule inhibitors of the Sec61 translocon. Using siRNA-mediated depletion of specific ER components, in combination with the potent Sec61 inhibitor ipomoeassin F (Ipom-F), we show that type III TMPs utilise a distinct pathway for membrane integration at the ER. Hence, following SRP-mediated delivery to the ER, type III TMPs can uniquely access the membrane insertase activity of the ER membrane complex (EMC) via a mechanism that is facilitated by the Sec61 translocon. This alternative EMC-mediated insertion pathway allows type III TMPs to bypass the Ipom-F-mediated blockade of membrane integration that is seen with obligate Sec61 clients.
    • BioID-based proteomic analysis of the Bid interactome identifies novel proteins involved in cell-cycle-dependent apoptotic priming

      Pedley, Robert; orcid: 0000-0002-0801-7240; King, Louise E.; Mallikarjun, Venkatesh; Wang, Pengbo; Swift, Joe; Brennan, Keith; Gilmore, Andrew P.; orcid: 0000-0002-9988-0436; email: agilmore@manchester.ac.uk (Nature Publishing Group UK, 2020-10-16)
      Abstract: Apoptotic priming controls the commitment of cells to apoptosis by determining how close they lie to mitochondrial permeabilisation. Variations in priming are important for how both healthy and cancer cells respond to chemotherapeutic agents, but how it is dynamically coordinated by Bcl-2 proteins remains unclear. The Bcl-2 family protein Bid is phosphorylated when cells enter mitosis, increasing apoptotic priming and sensitivity to antimitotic drugs. Here, we report an unbiased proximity biotinylation (BioID) screen to identify regulators of apoptotic priming in mitosis, using Bid as bait. The screen primarily identified proteins outside of the canonical Bid interactome. Specifically, we found that voltage-dependent anion-selective channel protein 2 (VDAC2) was required for Bid phosphorylation-dependent changes in apoptotic priming during mitosis. These results highlight the importance of the wider Bcl-2 family interactome in regulating the temporal control of apoptotic priming.
    • Divergent clonal evolution of blastic plasmacytoid dendritic cell neoplasm and chronic myelomonocytic leukemia from a shared TET2-mutated origin

      Batta, Kiran; orcid: 0000-0002-3494-0979; email: kiran.batta@manchester.ac.uk; Bossenbroek, Hasse M.; orcid: 0000-0002-6649-5363; Pemmaraju, Naveen; Wilks, Deepti P.; Chasty, Richard; Dennis, Mike; Milne, Paul; orcid: 0000-0002-8278-0463; Collin, Matthew; orcid: 0000-0001-6585-9586; Beird, Hannah C.; orcid: 0000-0002-5078-534X; Taylor, Justin; orcid: 0000-0003-4407-6325; et al. (Nature Publishing Group UK, 2021-04-08)