Dataset Information

Repression of PRMT5-mediated dimethylation stabilizes vimentin and promotes metastasis in MTAP-loss lung cancer

ABSTRACT: Abstract The aggressive nature and poor prognosis of lung cancer led us to explore the mechanisms driving disease progression. Utilizing our invasive cell-based model, we identified methylthioadenosine phosphorylase (MTAP) and confirmed its suppressive effects on tumorigenesis and metastasis, and patients with low MTAP expression displayed worse overall and progression-free survival. Mechanistically, accumulation of methylthioadenosine substrate in MTAP-deficient cells reduced the level of protein arginine methyltransferase 5 (PRMT5)-mediated symmetric dimethylarginine (sDMA) modification on proteins. Vimentin was revealed as a novel dimethyl-protein with less dimethylation level in response to MTAP loss. The sDMA modification on vimentin reduces its protein abundance and trivially affects its filamentous structure. In MTAP-loss cells, lower sDMA level prevents ubiquitination-mediated vimentin degradation, thereby stabilizing vimentin, contributing to cell invasion. This inverse association of the MTAP/PRMT5 axis with vimentin proteins was clinically corroborated. Taken together, we propose a novel mechanism of vimentin post-translational regulation and provide new insights in metastasis.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

DISEASE(S): Lung Cancer

SUBMITTER: Yi-Ju Chen

LAB HEAD: Yi-Ju Chen

PROVIDER: PXD031192 | Pride | 2022-05-31

REPOSITORIES: Pride

ACCESS DATA

Similar Datasets

Project description:PRMT5 is the major enzyme that catalyzes the symmetric dimethylation of arginine (sDMA) in mammalian cells. Its activity is crucial for many biological processes including transcriptional regulation, mRNA processing, as well as DNA damage and repair. However, the protein substrates identified for PRMT5 have yet been limited in numbers, hindering the understanding of PRMT5 functions in normal as well as diseased cells. Herein we developed an optimized strategy for proteomic profiling of cellular sDMA and apply it to the discovery of novel PRMT5 substrates. Our results show that a combination of proteolytic digestion by the metalloprotease ulilysin and using electron-transfer dissociation with supplemental activation as the mass spectrometry method significantly increased sDMA site identification and localization after immuno-affinity enrichment. By employing SILAC-based differential quantitative proteomic approach and a PRMT5 specific inhibitor, we identified 325 sDMA sites being regulated by PRMT5, 220 being novel sites, which greatly expanded the number of PRMT5 substrates. Biochemical studies confirmed the newly discovered PRMT5 substrate, Plasminogen activator inhibitor 1 RNA-binding protein (SERBP1) and revealed that the RGG/RG motif in the central region of SERBP1 contains both PRMT5-catalyzed sDMA and Type I PRMT-catalyzed asymmetric dimethylation of arginine (aDMA). Unexpectedly, using the optimized methylarginine profiling strategy, we also discovered arginine trimethylation, a previously unknown type of modification, on the central RGG/RG region of SERBP1. By mutational studies we demonstrated that the trimethyl modification on R172 of SERBP1 regulates its recruitment to stress granule (SG) under oxidative stress, indicating a functional role of arginine trimethylation in the cell. Overall, the optimized profiling strategy not only enabled the identification of extensive, non-overlapping sDMA sites and novel PRMT5 substrates, but also revealed a potentially important new PTM, arginine trimethylation. The work lays the foundation for further investigations on the functional interplay of different methylation modifications on arginines, especially in the heavily methylated RGG/RG motif of many RNA-binding proteins.

Dataset Information

Repression of PRMT5-mediated dimethylation stabilizes vimentin and promotes metastasis in MTAP-loss lung cancer

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure