Unraveling the phospholipid identity of the gene expression compartments by Q-DC-dSTORM

0555746 - ÚMG 2022 RIV DE eng O - Others
Hoboth, Peter - Sztacho, Martin - Šebesta, O. - Hozák, Pavel
Unraveling the phospholipid identity of the gene expression compartments by Q-DC-dSTORM.
2021
R&D Projects: GA MŠMT(CZ) LM2018129; GA MŠMT(CZ) EF16_013/0001775; GA ČR GA19-05608S; GA ČR(CZ) GA18-19714S; GA MŠMT LTC19048; GA MŠMT LTC20024; GA MŠMT(CZ) ED1.1.00/02.0109
Institutional support: RVO:68378050
Keywords : quantitative dual-color direct stochastic optical reconstruction microscopy * nuclear phosphatidylinositol phosphates * nucleoplasm * nuclear speckles * RNA polymerase II transcription
OECD category: Cell biology

Single-molecule localization (SML) microscopy provided an unprecedented insight into the sub-nuclear organization of proteins and nucleic acids and helped to develop models that acknowledge formation of transcriptional condensates as a driving force of gene expression. However, the roles of nuclear lipids in the establishment of the functional nuclear architecture, apart from the nuclear envelope, has been neglected. Nevertheless, accumulating evidence suggests the involvement of nuclear lipids and particularly of phosphatidylinositol phosphates (PIPs) in gene expression. We used quantitative dual-color direct stochastic optical reconstruction microscopy (Q-DC-dSTORM) for the evaluation of the distribution of immunolabeled nuclear PIP while preserving the context of nuclear architecture. We revealed for the first time the spatial organization of nuclear phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2) and phosphatidylinositol 4-monophosphate (PI(4)P) within individual nuclear sub-compartments. PI(4,5)P2 is the most abundant nuclear PIP, while PI(4)P is a precursor for the biosynthesis of PI(4,5)P2 and PI(3,4)P2. We used Q-DC-dSTORM and analyzed the spatial relationship of PI(4,5)P2, PI(3,4)P2 and PI(4)P with the nuclear speckle marker SON and with RNA polymerase II (RNAPII). We compared the real data with random SMLs which allowed us to assess if the co-patterning of the two probes is non-random and visualized NNDs using self-developed in cellulo color-coded maps [1,5]. We found all three PIPs dispersed within SON matrix in the nuclear speckles and PI(4,5)P2 and PI(3,4)P2 in the close proximity with the subset of RNAPII foci. We showed PI(4,5)P2, PI(3,4)P2 and PI(4)P within nuclear speckles and in the nucleoplasmic foci and PI(4,5)P2 and PI(3,4)P2 in the close proximity with the subset of RNAII foci either in the nucleoplasm or nuclear speckles.
Permanent Link: http://hdl.handle.net/11104/0330205