scholarly journals Organella bezbłonowe a separacja faz ciecz-ciecz – metody ich badań

2020 ◽  
Vol 66 (2) ◽  
Author(s):  
Aneta Tarczewska ◽  
Krzysztof Wycisk ◽  
Nikola Sozańska ◽  
Andrzej Ożyhar
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Liquid Liquid Phase Separation ◽  
Disordered Regions

Organella bezbłonowe (MLOs, ang. membraneless organelles) stanowią sporą grupę kompartmentów wewnątrzkomórkowych formowanych na różnych etapach życia komórki. Są one niezbędnymi strukturami umożliwiającymi komórce pełnienie istotnych funkcji życiowych i właściwą odpowiedź na stres. MLOs obecne są zarówno w cytoplazmie jak i w innych organellach głównie w jądrze komórkowym. Powstają na drodze spontanicznej separacji faz ciecz‑ciecz (LLPS, ang. liquid-liquid phase separation) w odpowiedzi na zmieniające się czynniki fizykochemiczne mikrootoczenia. Składają się zarówno z białek które najczęściej posiadają regiony inherentnie nieuporządkowane (ang. intrinsically disordered regions, IDRs) jak i kwasów nukleinowych – głównie RNA. Niniejsza praca przedstawia informacje o biofizycznych podstawach formowania i funkcjonowania MLOs oraz zjawiska odpowiedzialnego za ich formowania, tj. LLPS. Zawiera także przegląd technik stosowanych w biochemii i biologii molekularnej, które za cel mają dostarczenie informacji o samoregulacji składu, struktury poszczególnych składników i ich lokalizacji oraz funkcjonalności danego MLO.

scholarly journals Transcription Regulators and Membraneless Organelles Challenges to Investigate Them

2021 ◽  
Vol 22 (23) ◽  
pp. 12758
Author(s):  
Katarzyna Sołtys ◽  
Andrzej Ożyhar
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Cellular Processes ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Experimental Systems ◽  
Transcription Regulators ◽  
Crucial Information ◽  
Liquid Liquid Phase Separation

Eukaryotic cells are composed of different bio-macromolecules that are divided into compartments called organelles providing optimal microenvironments for many cellular processes. A specific type of organelles is membraneless organelles. They are formed via a process called liquid–liquid phase separation that is driven by weak multivalent interactions between particular bio-macromolecules. In this review, we gather crucial information regarding different classes of transcription regulators with the propensity to undergo liquid–liquid phase separation and stress the role of intrinsically disordered regions in this phenomenon. We also discuss recently developed experimental systems for studying formation and properties of membraneless organelles.

scholarly journals The (un)structural biology of biomolecular liquid-liquid phase separation using NMR spectroscopy

2020 ◽  
Vol 295 (8) ◽  
pp. 2375-2384 ◽  
Author(s):  
Anastasia C. Murthy ◽  
Nicolas L. Fawzi
Keyword(s):  
Phase Separation ◽  
Nmr Spectroscopy ◽  
Liquid Phase ◽  
Structural Biology ◽  
Liquid Phase Separation ◽  
Biological Processes ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Molecular Aspects ◽  
Liquid Liquid Phase Separation

Liquid-liquid phase separation (LLPS) of proteins and nucleic acids is a phenomenon that underlies membraneless compartmentalization of the cell. The underlying molecular interactions that underpin biomolecular LLPS have been of increased interest due to the importance of membraneless organelles in facilitating various biological processes and the disease association of several of the proteins that mediate LLPS. Proteins that are able to undergo LLPS often contain intrinsically disordered regions and remain dynamic in solution. Solution-state NMR spectroscopy has emerged as a leading structural technique to characterize protein LLPS due to the variety and specificity of information that can be obtained about intrinsically disordered sequences. This review discusses practical aspects of studying LLPS by NMR, summarizes recent work on the molecular aspects of LLPS of various protein systems, and discusses future opportunities for characterizing the molecular details of LLPS to modulate phase separation.

scholarly journals Liquid-liquid phase separation of light-inducible transcription factors increases transcription activation in mammalian cells and mice

2021 ◽  
Vol 7 (1) ◽  
pp. eabd3568
Author(s):  
Nils Schneider ◽  
Franz-Georg Wieland ◽  
Deqiang Kong ◽  
Alexandra A. M. Fischer ◽  
Maximilian Hörner ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Phase Separation ◽  
Liquid Phase ◽  
Mammalian Cells ◽  
Liquid Phase Separation ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Gene Switches ◽  
Liquid Liquid Phase Separation

Light-inducible gene switches represent a key strategy for the precise manipulation of cellular events in fundamental and applied research. However, the performance of widely used gene switches is limited due to low tissue penetrance and possible phototoxicity of the light stimulus. To overcome these limitations, we engineer optogenetic synthetic transcription factors to undergo liquid-liquid phase separation in close spatial proximity to promoters. Phase separation of constitutive and optogenetic synthetic transcription factors was achieved by incorporation of intrinsically disordered regions. Supported by a quantitative mathematical model, we demonstrate that engineered transcription factor droplets form at target promoters and increase gene expression up to fivefold. This increase in performance was observed in multiple mammalian cells lines as well as in mice following in situ transfection. The results of this work suggest that the introduction of intrinsically disordered domains is a simple yet effective means to boost synthetic transcription factor activity.

scholarly journals Liquid–Liquid Phase Separation by Intrinsically Disordered Protein Regions of Viruses: Roles in Viral Life Cycle and Control of Virus–Host Interactions

2020 ◽  
Vol 21 (23) ◽  
pp. 9045 ◽  
Author(s):  
Stefania Brocca ◽  
Rita Grandori ◽  
Sonia Longhi ◽  
Vladimir Uversky
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Critical Role ◽  
Liquid Phase Separation ◽  
Temporal Organization ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Cell Functions ◽  
Intrinsically Disordered Regions ◽  
Liquid Liquid Phase Separation

Intrinsically disordered proteins (IDPs) are unable to adopt a unique 3D structure under physiological conditions and thus exist as highly dynamic conformational ensembles. IDPs are ubiquitous and widely spread in the protein realm. In the last decade, compelling experimental evidence has been gathered, pointing to the ability of IDPs and intrinsically disordered regions (IDRs) to undergo liquid–liquid phase separation (LLPS), a phenomenon driving the formation of membrane-less organelles (MLOs). These biological condensates play a critical role in the spatio-temporal organization of the cell, where they exert a multitude of key biological functions, ranging from transcriptional regulation and silencing to control of signal transduction networks. After introducing IDPs and LLPS, we herein survey available data on LLPS by IDPs/IDRs of viral origin and discuss their functional implications. We distinguish LLPS associated with viral replication and trafficking of viral components, from the LLPS-mediated interference of viruses with host cell functions. We discuss emerging evidence on the ability of plant virus proteins to interfere with the regulation of MLOs of the host and propose that bacteriophages can interfere with bacterial LLPS, as well. We conclude by discussing how LLPS could be targeted to treat phase separation-associated diseases, including viral infections.

scholarly journals G-quadruplex DNA inhibits unwinding activity but promotes liquid–liquid phase separation by the DEAD-box helicase Ded1p

2021 ◽  
Author(s):  
Jun Gao ◽  
Zhaofeng Gao ◽  
Andrea A. Putnam ◽  
Alicia K. Byrd ◽  
Sarah L. Venus ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Intrinsically Disordered ◽  
Dead Box ◽  
G4 Dna ◽  
G Quadruplex ◽  
The Dead ◽  
Liquid Liquid Phase Separation

G-quadruplex (G4) DNA inhibits RNA unwinding activity but promotes liquid–liquid phase separation of the DEAD-box helicase Ded1p in vitro and in cells. This highlights multifaceted effects of G4DNA on an enzyme with intrinsically disordered domains.

Charge pattern affects the structure and dynamics of polyampholyte condensates

2020 ◽  
Vol 22 (34) ◽  
pp. 19368-19375 ◽  
Author(s):  
Milan Kumar Hazra ◽  
Yaakov Levy
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Intrinsically Disordered Proteins ◽  
Liquid Phase Separation ◽  
Disordered Proteins ◽  
Internal Diffusion ◽  
Intrinsically Disordered ◽  
Structure And Dynamics ◽  
Liquid Liquid Phase Separation

The charge pattern of intrinsically disordered proteins affects the dynamics and internal diffusion of their condensate formed via liquid–liquid phase separation.

scholarly journals The Dynamism of Intrinsically Disordered Proteins in Liquid-Liquid Phase Separation

2020 ◽  
Vol 118 (3) ◽  
pp. 60a
Author(s):  
Samrat Mukhopadhyay ◽  
Anupa Majumdar ◽  
Priyanka Dogra ◽  
Shiny Maity ◽  
Ashish Joshi
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Intrinsically Disordered Proteins ◽  
Liquid Phase Separation ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Liquid Liquid Phase Separation
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