The Human Telomeric Proteome During Telomere Replication
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Cell Culture
SUBMITTER: 
Chih-Yi Gabriela Lin
LAB HEAD: Joachim Lingner
PROVIDER: PXD018712 | Pride | 2021-11-03
REPOSITORIES: Pride
Similar Datasets
Project description:Trichomonas vaginalis is a parasitic protist that infects the human urogenital tract. During the infection, trichomonads adhere to the host mucosa, acquire nutrients from the vaginal/prostate environment, and release small extracellular vesicles (sEVs) that contribute to the trichomonad adherenceand modulate the host-parasite communication. Approximately 40% - 70% of T. vaginalis strains harbor double-stranded RNA virus called Trichomonasvirus (TVV). Naked TVV particles have the potential to stimulate a proinflammatory response in human cells, however, the mode of TVV release from trichomonads to the environment is not clear. In this report, we showed for the first time that TVV particles are released from T. vaginalis cells within sEVs. The sEVs loaded with TVV stimulated a higher proinflammatory response of human HaCaT cells in comparison to sEVs from TVV negative parasites. Moreover, a comparison of T. vaginalis isogenic TVV plus and TVV minus clones revealed a significant impact of TVV infection on the sEV proteome and RNA cargo. Small EVs from TVV positive trichomonads contained 12 enriched and 8 unique proteins including membrane-associated BspA adhesine, and about a 2.5-fold increase in the content of small regulatory tsRNA. As T. vaginalis isolates are frequently infected with TVV, the release of TVV via sEVs to the environment represents an important factor with the potential to enhance inflammation-related pathogenesis during trichomoniasis.
2022-04-22 | PXD031790 | Pride
Project description:Genomic instability associated with DNA replication stress is linked to cancer and genetic pathologies in humans. If not properly regulated, replication stress, such as fork stalling and collapse, can be induced at natural replication impediments present throughout the genome. The fork protection complex (FPC) is thought to play a critical role in stabilizing stalled replication forks at several known replication barriers including eukaryotic rDNA genes and the fission yeast mating-type locus. However, little is known about the role of the FPC at other natural impediments including telomeres. Telomeres are considered to be difficult to replicate due to the presence of repetitive GT-rich sequences and telomere-binding proteins. However, the regulatory mechanism that ensures telomere replication is not fully understood. Here, we report the role of the fission yeast Swi1/Timeless, a subunit of the FPC, in telomere replication. Loss of Swi1 causes telomere shortening in a telomerase-independent manner. Our epistasis analyses suggest that heterochromatin and telomere-binding proteins are not major impediments for telomere replication in the absence of Swi1. Instead, repetitive DNA sequences impair telomere integrity in swi1Î mutant cells, leading to the loss of repeat DNA. In the absence of Swi1, telomere shortening is accompanied with an increased recruitment of Rad52 recombinase and more frequent amplification of telomere/subtelomeres, reminiscent of tumor cells that utilize the alternative lengthening of telomeres pathway (ALT) to maintain telomeres. These results suggest that Swi1 ensures telomere replication by suppressing recombination and repeat instability at telomeres. Our studies may also be relevant in understanding the potential role of the FPC in regulation of telomere stability in cancer cells. Genome-wide distributions of Rad52 in wild type and in swi1 deletion in fission yeast The'SP1173_WT ChIP-seq' is an input sample (non-tagged data).
2016-02-25 | E-GEOD-74487 | biostudies-arrayexpress
Project description:The two non-visual arrestin isoforms, arrestin2 and arrestin3, recognize and bind hundreds of G protein-coupled receptors (GPCRs) with different phosphorylation patterns leading to distinct functional outcomes. Whereas the impact of phosphorylation of the vasopressin 2 receptor and rhodopsin on arrestin interactions has been well studied, much less known for other GPCRs. Here we have characterized the interaction between the phosphorylated CC chemokine receptor 5 (CCR5) and arrestin2. Mass spectrometry and biochemical revealed several new CCR5 phosphorylation sites, which proved essential for the formation of stable complexes with arrestin2. Crystal structures of arrestin2 in apo form and in complexes with two CCR5 C-terminal phosphopeptides revealed three key CCR5 phosphoresidues in a pXpp motif that form extensive interactions with arrestin2 and lead to activation. The same phosphoresidue-cluster is present in other receptors which form stable complexes with arrestin2. The contributions of each CCR5 phosphoresidue on arrestin2 conformation and binding have been characterized by a combination of NMR spectroscopy, biochemical and functional assays. We propose that the identified pXpp motif is responsible for robust arrestin2 recruitment in many GPCRs. Moreover, an analysis of available sequence, structural and functional information on other GPCR arrestin interactions suggests a particular spatial arrangement of phosphoresidues within the GPCR intracellular loops and C-terminal tail determines arrestin2 and 3 isoform specificity.
2023-05-24 | PXD036220 | Pride
Project description:Genomic instability associated with DNA replication stress is linked to cancer and genetic pathologies in humans. If not properly regulated, replication stress, such as fork stalling and collapse, can be induced at natural replication impediments present throughout the genome. The fork protection complex (FPC) is thought to play a critical role in stabilizing stalled replication forks at several known replication barriers including eukaryotic rDNA genes and the fission yeast mating-type locus. However, little is known about the role of the FPC at other natural impediments including telomeres. Telomeres are considered to be difficult to replicate due to the presence of repetitive GT-rich sequences and telomere-binding proteins. However, the regulatory mechanism that ensures telomere replication is not fully understood. Here, we report the role of the fission yeast Swi1/Timeless, a subunit of the FPC, in telomere replication. Loss of Swi1 causes telomere shortening in a telomerase-independent manner. Our epistasis analyses suggest that heterochromatin and telomere-binding proteins are not major impediments for telomere replication in the absence of Swi1. Instead, repetitive DNA sequences impair telomere integrity in swi1Δ mutant cells, leading to the loss of repeat DNA. In the absence of Swi1, telomere shortening is accompanied with an increased recruitment of Rad52 recombinase and more frequent amplification of telomere/subtelomeres, reminiscent of tumor cells that utilize the alternative lengthening of telomeres pathway (ALT) to maintain telomeres. These results suggest that Swi1 ensures telomere replication by suppressing recombination and repeat instability at telomeres. Our studies may also be relevant in understanding the potential role of the FPC in regulation of telomere stability in cancer cells.
2016-02-25 | GSE74487 | GEO
Project description:Deoxyhypusine synthase (DHS) is encoded by a nuclear gene and is the key enzyme involved in the post-translational activation of the eukaryotic translation initiation factor eIF5A. DHS plays important roles in plant growth and development. To gain a better understanding of DHS, the petunia (Petunia hybrida) PhDHS gene was isolated, and the role of PhDHS in plant growth was analysed. PhDHS protein was localized to the nucleus and cytoplasm. Virus-mediated PhDHS silencing caused a sectored chlorotic leaf phenotype. The chlorophyll levels was reducted and the development of chloroplasts was abnormal in PhDHS-silenced leaves These features were not observed in DHS-suppressed Arabidopsis thaliana and Solanum lycopersicum. These results indicated that PhDHS is required for development in petunia. A proteome assay showed that 308 proteins are up-regulated and 266 proteins are down-regulated in PhDHS-silenced plants compared with control. Among them, 20 proteins in photosystem I and photosystem II and 11 thylakoid proteins were down-regulated in PhDHS-silenced leaves, further supporting the involvement of PhDHS in photosynthesis in petunia.
2019-11-13 | PXD012227 | Pride
Project description:Telomeres play crucial roles during tumorigenesis inducing cellular senescence upon telomere shortening and extensive chromosome instability during telomere crisis. However, it has not been investigated if and how cellular transformation and oncogenic stress alters telomeric chromatin composition and function. Here we transform human fibroblasts by consecutive transduction with vectors expressing hTERT, the SV40 early region and activated H-RasV12. Pairwise comparisons of the telomeric proteome during different stages of transformation reveals upregulation of proteins involved in chromatin remodeling, DNA repair and replication at chromosome ends. Depletion of several of these proteins induces telomere fragility indicating their roles in replication of telomeric DNA. Depletion of SAMHD1, which has reported roles in DNA resection and homology directed repair, leads to telomere breakage events in cells deprived of the shelterin component TRF1. Thus our analysis identifies factors, which accumulate at telomeres during cellular transformation to promote telomere replication and repair, resisting oncogene-borne telomere replication stress.
2018-07-13 | PXD010088 | Pride
Project description:Increased treatment of metastatic castration resistant prostate cancer (mCRPC) with second-generation anti-androgen therapies (ADT) has coincided with a greater incidence of lethal, aggressive variant prostate cancer (AVPC) tumors that have lost androgen receptor (AR) signaling. AVPC tumors may also express neuroendocrine markers, termed neuroendocrine prostate cancer (NEPC). Recent evidence suggests kinase signaling may be an important driver of NEPC. To identify targetable kinases in NEPC, we performed global phosphoproteomics comparing AR-negative to AR-positive prostate cancer cell lines and identified multiple altered signaling pathways, including enrichment of RET kinase activity in the AR-negative cell lines. Clinical NEPC and NEPC patient derived xenografts displayed upregulated RET transcript and RET pathway activity. Pharmacologically inhibiting RET kinase in NEPC models dramatically reduced tumor growth and cell viability in mouse and human NEPC models. Our results suggest that targeting RET in NEPC tumors with high RET expression may be a novel treatment option.
2020-05-29 | PXD012970 | Pride
Project description:Increased treatment of metastatic castration resistant prostate cancer (mCRPC) with second-generation anti-androgen therapies (ADT) has coincided with a greater incidence of lethal, aggressive variant prostate cancer (AVPC) tumors that have lost androgen receptor (AR) signaling. AVPC tumors may also express neuroendocrine markers, termed neuroendocrine prostate cancer (NEPC). Recent evidence suggests kinase signaling may be an important driver of NEPC. To identify targetable kinases in NEPC, we performed global phosphoproteomics comparing AR-negative to AR-positive prostate cancer cell lines and identified multiple altered signaling pathways, including enrichment of RET kinase activity in the AR-negative cell lines. Clinical NEPC and NEPC patient derived xenografts displayed upregulated RET transcript and RET pathway activity. Pharmacologically inhibiting RET kinase in NEPC models dramatically reduced tumor growth and cell viability in mouse and human NEPC models. Our results suggest that targeting RET in NEPC tumors with high RET expression may be a novel treatment option.
2020-05-29 | PXD012971 | Pride
Project description:Chromatin organization must be maintained during cell proliferation to preserve cellular identity and genome integrity. However, DNA replication results in transient displacement of DNA bound proteins, and it is unclear how they regain access to newly replicated DNA. Using quantitative MS-based proteomics coupled to Nascent Chromatin Capture, we provide time resolved binding kinetics for thousands of proteins behind replisomes within euchromatin and heterochromatin in human cells. This shows that most proteins regain access within the first 15 minutes after the passage of the fork. In contrast, 30% of the identified proteins do not, and this delay cannot be inferred from their known function, physicochemical properties, or nuclear abundance. Instead, differential chromatin organization affect their reassociation. We provide evidence that DNA replication not only disrupts but also promotes recruitment of transcription factors and chromatin remodellers, providing a significant advance in understanding how DNA replication could contribute to programmed changes of cell memory.We include here a reference to link the data with our manuscript:Tables SUPP1 and SUPP2:NCC data: PT7988 (Bio-rep1), PT8242 (Bio-rep2), PT8243 (Bio-rep3). 1-24 (24 high-pH RPLC fractions from TMT labeled peptides)Nuclear fraction data: PT7988 (Bio-rep1), PT8242 (Bio-rep2), PT8243 (Bio-rep3). 25-48 (24 high-pH RPLC fractions from TMT labeled peptides)Tables SUPP3-5:NCC data: PT9825 (Bio-rep1), PT9825 (Bio-rep2), PT9825 (Bio-rep3). (11-34, 35-58, 59-82) (24 high-pH RPLC fractions from TMT labeled peptides)Nuclear fraction data: PT9825 (Bio-rep1), PT9825 (Bio-rep2), PT9825 (Bio-rep3). (83-106, 107-130, 131-154). (24 high-pH RPLC fractions from TMT labeled peptides)
2023-02-02 | PXD035489 | Pride
Project description:CDK4/6 kinase inhibitors have shown great promise in clinical trials in various cancer types and have recently entered clinical trial for advanced prostate cancer. Although patients are expected to respond well to this class of drugs, development of resistance in some patients is anticipated. To pre-empt this and study how prostate cancer may evade CDK4/6 inhibition, new resistance models were generated from LNCaP and LAPC4 prostate cancer cells cells by prolonged culturing in presence of 0.5uM palbociclib. A shotgun phosphoproteomics approach was utilized and integrated with RNA sequencing data to unravel the molecular underpinnings of acquired resistance to palbociclib and resultant broad CDK4/6 inhibitor resistance.
2018-05-16 | PXD006561 | Pride