Dataset Information

InstaNovo-P: A de novo peptide sequencing model for phosphoproteomics

ABSTRACT: Phosphorylation, a crucial post-translational modification (PTM), plays a central role in cellular signaling and disease mechanisms. Mass spectrometry-based phosphoproteomics is widely used for system-wide characterization of phosphorylation events. However, traditional methods struggle with accurate phosphorylated site localization, complex search spaces, and detecting sequences outside the reference database. Advances in de novo peptide sequencing offer opportunities to address these limitations, but have yet to become integrated and adapted for phosphoproteomics datasets. Here, we present InstaNovo-P, a phosphorylation specific version of our transformer-based InstaNovo model, fine-tuned on extensive phosphoproteomics datasets. InstaNovo-P significantly surpasses existing methods in phosphorylated peptide detection and phosphorylated site localization accuracy across multiple datasets, including complex experimental scenarios. Our model robustly identifies peptides with single and multiple phosphorylated sites, effectively localizing phosphorylation events on serine, threonine, and tyrosine residues. We experimentally validate our model predictions by studying FGFR2 signaling, further demonstrating that InstaNovo-P uncovers phosphorylated sites previously missed by traditional database searches. These predictions align with critical biological processes, confirming the model’s capacity to yield valuable biological insights. InstaNovo-P adds value to phosphoproteomics experiments by effectively identifying biologically relevant phosphorylation events without prior information, providing a powerful analytical tool for the dissection of signaling pathways.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Breast Epithelium, Cell Culture

DISEASE(S): Breast Cancer

SUBMITTER: Vahap Canbay

LAB HEAD: Konstantinos Kalogeropoulos

PROVIDER: PXD074105 | Pride | 2026-05-20

REPOSITORIES: pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	20260126_MH_ELBE_VC_uPAC50_68min_0000_DIA_DeNovo_WT_1.raw	Raw
	20260126_MH_ELBE_VC_uPAC50_68min_0000_DIA_DeNovo_WT_2.raw	Raw
	20260205_134604_20260126_WT_INP_V2.sne	Other
	checksum.txt	Txt

Items per page:

1 - 4 of 4

Similar Datasets

Project description:Dysregulated kinase activity drives oncogenic signalling, perturbs cellular homeostasis, and promotes tumour progression. Despite major success in targeting kinases therapeutically, the downstream consequences of kinase inhibition and the mechanisms underlying drug resistance remain incompletely understood. One of the most frequent oncogenic kinase mutations, BRAFV600E, constitutively activates the MAPK pathway and represents a major therapeutic target in melanoma and other cancers. However, the functional relevance of most phosphorylation events downstream of BRAF signalling is unknown, limiting mechanistic interpretation and rational therapeutic design. Here, we established a global, multi-omic model of BRAF inhibition response in BRAFV600E-mutant melanoma cells by integrating time-resolved phosphoproteomics, biophysical PTM-proteomics, transcriptomics, and thermal proteome profiling. Our ultradeep phosphoproteomic analysis revealed widespread phosphorylation changes upon Dabrafenib treatment, while biophysical phosphoproteomics uncovered phosphorylation events associated with altered solubility and subcellular localisation, indicative of biomolecular condensation and nuclear reorganisation. Integration of these modalities into a network-based mechanistic model enabled the prioritisation of functionally relevant phosphorylation sites and kinases. Experimental validation confirmed CDK9, CLK3, and TNIK as key regulators of BRAFV600E signalling and as candidate targets for combinatorial inhibition strategies capable of re-sensitising resistant melanoma cells in a synthetic lethal manner. The transcription factor ETV3 emerged from the network as a previously unrecognised effector of oncogenic BRAF signalling. Using phosphosite-specific biophysical data, imaging, and FRAP experiments, we demonstrated that ETV3 phosphorylation controls its DNA-binding kinetics. Functional assays combining ETV3 knockdown, metabolomics, and drug screening revealed that ETV3 modulates transcriptional and metabolic responses to BRAF inhibition, linking oncogenic signalling to metabolic rewiring. Together, this study provides a comprehensive systems-level framework that connects phosphorylation dynamics to protein function and cellular phenotype, highlights ETV3 as a novel signalling node, and illustrates how multi-omic, site-resolved network models can reveal actionable mechanisms of kinase-driven oncogenesis.

Project description:Spt6 is a multifunctional histone chaperone involved in the maintenance of chromatin structure during elongation by RNA polymerase II (Pol II). Spt6 has a tandem SH2 (tSH2) domain within its C-terminus that recognizes Pol II CTD peptides phosphorylated on Ser2, Ser5 or Try1 in vitro. Deleting the tSH2 domain, however, only has a partial effect on Spt6 occupancy in vivo, suggesting that more complex mechanisms are involved in the Spt6 recruitment. Our results show that the Ser2 kinases Bur1 and Ctk1, but not the Ser5 kinase Kin28, cooperate in recruiting Spt6, genome-wide. Interestingly, the Ser2 kinases promote the association of Spt6 in early transcribed regions and not toward the 3' end of genes, where phosphorylated Ser2 reaches its maximum level. Additionally, our results uncover an unexpected role for histone deacetylases (Rpd3 and Hos2) in promoting Spt6 interaction with elongating Pol II. Finally, our data suggest that phosphorylation of the Pol II CTD on Tyr1 promotes the association of Spt6 with the 3' end of transcribed genes, independently of Ser2 phosphorylation. Collectively, our results show that a complex network of interactions, involving the Spt6 tSH2 domain, CTD phosphorylation and histone deacetylases, coordinate the recruitment of Spt6 to transcribed genes in vivo. We examined the genome-wide distribution (using ChIP-chip) of Spt6. Spt6 occupancy was also assayed in mutants for CTD Serine 2 and Serine 5 kinases and in mutants for histone deacetylases. ChIPs were performed with a Myc-tagged version of Spt6. Most ChIPs (in Cy5) were hybridyzed against a control ChIP sample from an isogenic non-tagged strain (in Cy3). In the ChIP experiments with the spt6-202del mutant, non immunoprecipitated DNA (input) was used as the control. In addition to Spt6 ChIPs, the project includes RNAPII (Rpb3) ChIP-chip datasets, where an anti-Rpb3 antibody was used to ChIP RNAPII and non immunoprecipitated DNA (input) was used as the control. All ChIP-chip experiments were done in duplicates. Each microarray was normalized using the Lima Loess and replicates were combined using a weighted average method as previously described (Pokholok et al., 2005).

Dataset Information

InstaNovo-P: A de novo peptide sequencing model for phosphoproteomics

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets