Quatrième réunion annuelle du GDR Architecture et Dynamique du Noyau et des Génomes (ADN&G)

Session

Oral

Non programmé

salle de conférence "4R4 - Nicole Le Douarin" (CBI Toulouse)

5. An in vivo degradation system to study cross-talk between topoisomerases in E. coli

Céline Borde (CIRB CDF)

During the E. coli cell cycle, DNA is exposed to coiling variations induced by biological processes such as replication or transcription. Four topoisomerases contribute to the maintenance of DNA homeostasis (TopoI, Gyrase, TopoIII and TopoIV). Among them, TopoI which function appeared to be mostly linked to the relaxation of negative supercoils induced by transcription and TopoIV that promotes...

11. Chromatin and nucleoplasm motions in response to DNA damage

Pierre-Alexandre Vidi (Institut de Cancérologie de l'Ouest)

Maelle Locatelli2, Chloé Hommais1, Fadil Iqbal3, Keith Bonin4, Kerry Bloom2, Jing Liu3, and Pierre-Alexandre Vidi1

1 Institut de Cancérologie de l’Ouest, Angers, France
2 Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, USA
3 Department of Physics, Purdue University, West-Lafayette, USA
4 Department of Physics, Wake Forest University, Winston-Salem,...

3. Controlled liquid-like droplet formation of ParBS complexes through CTP binding and hydrolysis during bacterial DNA segregation

Mlle Linda Delimi (Laboratoire Charles Coulomb)

The bacterial DNA segregation is mainly performed with the ParABS system. It is composed of ParB, a binding protein, ParA, an ATPase and parS, a specific binding DNA sequence that ParB binds parS with high affinity. Hundreds of ParB are recruited around parS into a complex, called ParBS, which displays liquid-like properties.

Recently, it has been shown that ParB is using energy stored as...

10. Exploring model of chromosome in vivo : ribosomal DNA and nucleolus

Olivier GADAL (Centre de Biologie Intégrative (CBI), UMR5077 CNRS, bat IBCG)

Claudie Carron1, Carine Dominique1, Nana Kadidia Maiga 1, Mickaël Lelek2, Thomas Mangeat3, Frédéric Beckouët1, Christian Rouvière3, Isabelle Léger-Silvestre1, Sylvain Cantaloube3, Christophe Zimmer2, Anthony K. Henras1, Benjamin Albert1and Olivier Gadal1.

1: MCD (CBI), Université de Toulouse, CNRS, UPS, 31000, Toulouse, France

2: Imaging and Modeling Unit, Department of...

2. Exploring uracil base opening dynamics in dsDNA through enhanced molecular dynamics simulations

Dr Vinnarasi SARAVANAN (University of Lille)

Uracil can exist in dsDNA by spontaneous cytosine deamination or by misincorporation of dUMP instead of dTMP during the replication process [1]. A highly specific Uracil-DNA glycosylase (UDG) enzyme recognizes and excise the flipped uracil base from the dsDNA helix; this mechanism is part of the base-excision repair (BER) pathway [2]. There remains a lack of complete understanding in the...

9. Histone ADP-ribosylation controls early multi-scale chromatin dynamics upon DNA damage

fabiola garcia fernandez (INSERM)

ADP-ribosylation signaling by PARP1 is a key early event of the DNA damage response (DDR). PARP1 recruitment occurs within seconds upon DNA damage, triggering the accumulation of ADP-ribose binding repair factors and regulating chromatin architecture at sites of DNA damage. Histones, which are the second main target of this signaling pathway after PARP1 itself, are ADP-ribosylated, causing a...

14. Lamin A/C deficiency re-wires transcription factor footprints and inhibits EMT

Philippe Collas (University of Oslo)

Recent studies suggest an involvement of nuclear lamins in the epithelial-to-mesenchymal transition (EMT) and cancer progression. However, the extent to which nuclear lamins, as genome organizers, are implicated in EMT remains both not consensual and unclear. We have addressed the role of A-type lamins (lamin A/C) in an MCF10A breast epithelial cell model of EMT induction by TGFβ. LMNA...

4. Mechanism of bacterial DNA segregation: LLPS behavior, beyond trend and reality

Perrine Revoil (Université Toulpuse III Paul Sabatier - Laboratoire de Microbiologie et Génétique Moléculaires)

In bacteria, low-copy-number replicons carry self-specific partition systems to ensure their faithful segregation. Among these systems, ParABS partition systems, consisting of a Walker-type ATPase (ParA) and a DNA-binding protein (ParB) along with parS centromere sites, are the most prevalent on plasmids and the only one present on chromosomes. ParB proteins, recently shown to belong to a...

12. Replicon dynamics during the cell cycle in Escherichia coli

Iris Veyrier (LMGM CBI)

During cell cycle, the bacteria must transmit all the genetic information it contains to its daughter cells. To do this, the chromosome and the plasmids, which form the replicons, must be duplicated through replication, then segregated in each daughter cell. However, replication and segregation events must be finely coordinated with cell division. Many proteins are involved in the regulation...

6. RNA profiling of molecular crowed nuclear micro-environments

Nathan Lecouvreur (IGMM)

Studying nuclear micro-environments, particularly membrane-less organelles (MLO) like Cajal-bodies, PML-bodies, speckles or paraspeckles, has always been a challenge. Indeed, such MLO constitute micro-environments with high molecular crowding which typically result from liquid-liquid phase separation. However, the isolation of such liquid-like droplets and the characterization of their...

8. Rules of engagement for condensins and cohesins guide mitotic chromosome formation

Leonid Mirny (MIT and Institut Curie)

During mitosis, interphase chromatin is rapidly converted into rod-shaped mitotic chromosomes. Using Hi-C, imaging, proteomics and polymer modeling, we determine how the activity and interplay between loop-extruding SMC motors accomplishes this dramatic transition. Our work reveals rules of engagement for SMC complexes that are critical for allowing cells to refold interphase chromatin into...

18. Single-molecule tracking reveals the functional allocation, in vivo interactions, and spatial organization of universal transcription factor NusG

Hafez El Sayyed (University of Oxford)

During transcription elongation, NusG aids RNA polymerase by inhibiting pausing, promoting anti-termination on rRNA operons, coupling transcription with translation on mRNA genes, and facilitating Rho-dependent termination. Despite extensive work, the in vivo functional allocation and spatial distribution of NusG remain unknown. Using single-molecule tracking and super-resolution imaging in...

1. Study of the role of the bacteriophage T4 protein, Ndd in the disorganization of the bacterial nucleoid in E. coli

Justine Groseille (1 Dynamique des chromosomes - CIRB, College de de France et Institut Pasteur)

Study of the role of the bacteriophage T4 protein, Ndd in the disorganization of the bacterial nucleoid in E. coli

Justine Groseille1, 2 (groseillejustine@gmail.com),Cristian Ilioaia4, Agnès Thierry2, Cristian Ilioaia4, Romain Koszul2, Olivier Espéli1

1 Dynamique des chromosomes - CIRB, College de de France, PARIS, France
2 UMR3525- Regulation spatiale des génomes, Institut Pasteur,...

17. The role of histone acetylation in sub-megabase chromatin folding

Frédéric Bantignies (CNRS)

Genome 3D organization is highly complex, made of several layers of organization from nucleosome to chromosome territory. At the Megabase scale, the genome is partitioned into Topologically Associating Domains (TADs), that may define functional genomic units. TADs are mostly revealed by cell population-based assays such Hi-C and their organization is defined by the extrusion action of cohesin...