Amandine Ferrand

An essential role for α4A-tubulin in platelet biogenesis.

During platelet biogenesis, microtubules (MTs) are arranged into submembranous structures (the marginal band) that encircle the cell in a single plane. This unique MT array has no equivalent in any other mammalian cell, and the mechanisms responsible for this particular mode of assembly are not fully understood. One possibility is that platelet MTs are composed of a particular set of tubulin isotypes that carry specific posttranslational modifications. Although β1-tubulin is known to be essential, no equivalent roles of α-tubulin isotypes in platelet formation or function have so far been reported. Here, we identify α4A-tubulin as a predominant α-tubulin isotype in platelets. Similar to β1-tubulin, α4A-tubulin expression is up-regulated during the late stages of megakaryocyte differentiation. Missense mutations in the α4A-tubulin gene cause macrothrombocytopenia in mice and humans. Defects in α4A-tubulin lead to changes in tubulin tyrosination status of the platelet tubulin pool. Ultrastructural defects include reduced numbers and misarranged MT coils in the platelet marginal band. We further observed defects in megakaryocyte maturation and proplatelet formation in -mutant mice. We have, thus, discovered an α-tubulin isotype with specific and essential roles in platelet biogenesis.

Purification of tubulin with controlled post-translational modifications by

In vitro reconstitutions of microtubule assemblies have provided essential mechanistic insights into the molecular bases of microtubule dynamics and their interactions with associated proteins. The tubulin code has emerged as a regulatory mechanism for microtubule functions, which suggests that tubulin isotypes and post-translational modifications (PTMs) play important roles in controlling microtubule functions. To investigate the tubulin code mechanism, it is essential to analyze different tubulin variants in vitro. Until now, this has been difficult, as most reconstitution experiments have used heavily post-translationally modified tubulin purified from brain tissue. Therefore, we developed a protocol that allows purification of tubulin with controlled PTMs from limited sources through cycles of polymerization and depolymerization. Although alternative protocols using affinity purification of tubulin also yield very pure tubulin, our protocol has the unique advantage of selecting for fully functional tubulin, as non-polymerizable tubulin is excluded in the successive polymerization cycles. It thus provides a novel procedure for obtaining tubulin with controlled PTMs for in vitro reconstitution experiments. We describe specific procedures for tubulin purification from adherent cells, cells grown in suspension cultures and single mouse brains. The protocol can be combined with drug treatment, transfection of cells before tubulin purification or enzymatic treatment during the purification process. The amplification of cells and their growth in spinner bottles takes ~13 d; the tubulin purification takes 6–7 h. The tubulin can be used in total internal reflection fluorescence (TIRF)-microscopy-based experiments or pelleting assays for the investigation of intrinsic properties of microtubules and their interactions with associated proteins.

https://www.nature.com/articles/s41596-019-0153-7

Loss of the deglutamylase CCP5 perturbs multiple steps of spermatogenesis and leads to male

Sperm cells are highly specialized mammalian cells, and their biogenesis requires unique intracellular structures. Perturbation of spermatogenesis often leads to male infertility. Here, we assess the role of a post-translational modification of tubulin, glutamylation, in spermatogenesis. We show that mice lacking the tubulin deglutamylase CCP5 (also known as AGBL5) do not form functional sperm. In these mice, spermatids accumulate polyglutamylated tubulin, accompanied by the occurrence of disorganized microtubule arrays, in particular in the sperm manchette. Spermatids further fail to re-arrange their intracellular space and accumulate organelles and cytosol, while nuclei condense normally. Strikingly, spermatids lacking CCP5 show supernumerary centrioles, suggesting that glutamylation could control centriole duplication. We show that most of these observed defects are also present in mice in which CCP5 is deleted only in the male germ line, strongly suggesting that they are germ-cell autonomous. Our findings reveal that polyglutamylation is, beyond its known importance for sperm flagella, an essential regulator of several microtubule-based functions during spermatogenesis. This makes enzymes involved in glutamylation prime candidates for being genes involved in male sterility.

Kinesin-3 Responds to Local Microtubule Dynamics to Target Synaptic Cargo Delivery to the

Neurons in the CNS establish thousands of en passant synapses along their axons. Robust neurotransmission depends on the replenishment of synaptic components in a spatially precise manner. Using live-cell microscopy and single-molecule reconstitution assays, we find that the delivery of synaptic vesicle precursors (SVPs) to en passant synapses in hippocampal neurons is specified by an interplay between the kinesin-3 KIF1A motor and presynaptic microtubules. Presynaptic sites are hotspots of dynamic microtubules rich in GTP-tubulin. KIF1A binds more weakly to GTP-tubulin than GDP-tubulin and competes with end-binding (EB) proteins for binding to the microtubule plus end. A disease-causing mutation within KIF1A that reduces preferential binding to GDP- versus GTP-rich microtubules disrupts SVP delivery and reduces presynaptic release upon neuronal stimulation. Thus, the localized enrichment of dynamic microtubules along the axon specifies a localized unloading zone that ensures the accurate delivery of SVPs, controlling presynaptic strength in hippocampal neurons.

Lana Ghanem

Patricia Uguen

The anti-cancer drug 5-fluorouracil affects cell cycle regulators and potential regulatory long

5-fluorouracil (5-FU) was isolated as an inhibitor of thymidylate synthase, which is important for DNA synthesis. The drug was later found to also affect the conserved 3′-5′ exoribonuclease EXOSC10/Rrp6, a catalytic subunit of the RNA exosome that degrades and processes protein-coding and non-coding transcripts. Work on 5-FU’s cytotoxicity has been focused on mRNAs and non-coding transcripts such as rRNAs, tRNAs and snoRNAs. However, the effect of 5-FU on long non-coding RNAs (lncRNAs), which include regulatory transcripts important for cell growth and differentiation, is poorly understood. RNA profiling of synchronized 5-FU treated yeast cells and protein assays reveal that the drug specifically inhibits a set of cell cycle regulated genes involved in mitotic division, by decreasing levels of the paralogous Swi5 and Ace2 transcriptional activators. We also observe widespread accumulation of different lncRNA types in treated cells, which are typically present at high levels in a strain lacking EXOSC10/Rrp6. 5-FU responsive lncRNAs include potential regulatory antisense transcripts that form double-stranded RNAs (dsRNAs) with overlapping sense mRNAs. Some of these transcripts encode proteins important for cell growth and division, such as the transcription factor Ace2, and the RNA exosome subunit EXOSC6/Mtr3. In addition to revealing a transcriptional effect of 5-FU action via DNA binding regulators involved in cell cycle progression, our results have implications for the function of putative regulatory lncRNAs in 5-FU mediated cytotoxicity. The data raise the intriguing possibility that the drug deregulates lncRNAs/dsRNAs involved in controlling eukaryotic cell division, thereby highlighting a new class of promising therapeutical targets.

Transcription-dependent spreading of the Dal80 yeast GATA factor across the body of highly

GATA transcription factors are highly conserved among eukaryotes and play roles in transcription of genes implicated in cancer progression and hematopoiesis. However, although their consensus binding sites have been well defined in vitro, the in vivo selectivity for recognition by GATA factors remains poorly characterized. Using ChIP-Seq, we identified the Dal80 GATA factor targets in yeast. Our data reveal Dal80 binding to a large set of promoters, sometimes independently of GATA sites, correlating with nitrogen- and/or Dal80-sensitive gene expression. Strikingly, Dal80 was also detected across the body of promoter-bound genes, correlating with high expression. Mechanistic single-gene experiments showed that Dal80 spreading across gene bodies requires active transcription. Consistently, Dal80 co-immunoprecipitated with the initiating and post-initiation forms of RNA Polymerase II. Our work suggests that GATA factors could play dual, synergistic roles during transcription initiation and post-initiation steps, promoting efficient remodeling of the gene expression program in response to environmental changes.

Postdoctoral Position In Genome Integrity And Cancer

A1-year fully funded postdoctoral position with the possibility of extension (see below) is available in the “Homologous Recombination and Cancer” group headed by Dr. Aura Carreira at the Institut Curie, Orsay site (located in the campus of Paris SUD Univ., south of Paris), France.

Project description

Our lab interrogates the mechanisms of the cell to preserve genome integrity using human BRCA2 protein as a model. We are interested in the function of BRCA2 and the consequences of its mutation in breast cancer predisposition. During the last few years we have identified a new DNA binding domain in BRCA2 that is defective in breast cancer variants, defined a role of BRCA2 as mediator in meiotic recombination and contributed to the work that first describes BRCA2 hypomorphic variants conferring increased moderate risk of breast cancerRecently, we have uncovered a role of BRCA2 in mitosis that allows proper chromosome segregation. Which of the functions of BRCA2, when defective, drive tumor formation is a long-standing question that we are also investigating using functional assays and “omics” approaches.

In this project, the candidate will tackle relevant questions about the function of BRCA2 protein using cell biology and biochemistry tools.

Techniques: The project will involve cell imaging, biochemistry, protein purification, genetics, molecular biology.

Work environment

Our laboratory is part of the “Genotoxic Stress and Cancer” (UMR 3348 CNRS) Unit of the Institut Curie, Orsay site (France). The Department is dedicated to the study of the DNA damage response, genome instability, replication stress and gene regulation mechanisms in human and model organisms. The successful candidate will benefit from top-level scientific environment of Institut Curie, the expertise of the other groups working in our Unit, our collaborators on this project (Sophie Zinn-Justin, CEA, France), from state-of-the-art facilities available at Institut Curie.

Candidate requirements

  • Recent PhD with at least one first-author international publication
  • Enthusiastic and highly motivated researcher with strong interest in the mechanisms of preserving genome integrity
  • Ability to work independently
  • Excellent communication skills, fluency in English
  • The ideal candidate would have experience in one or more of the following areas: biochemistry, protein purification, cell imaging, DNA repair, molecular biology.

Following the 1-year contract, the candidate will have the opportunity to continue his/her project in the lab by applying to the different Fellowships available for postdocs (first deadline September).

To apply, please send: curriculum vitae, motivation letter and the names/contact information of 2/3 referees to Aura Carreira:   before April 30th.

The position is available immediately but the start date is flexible.

For more information about the interests of the group visit: https://science.curie.fr/equipe-carreira

Postdoctoral Position In Genome Integrity And Cancer

A1-year fully funded postdoctoral position with the possibility of extension (see below) is available in the “Homologous Recombination and Cancer” group headed by Dr. Aura Carreira at the Institut Curie, Orsay site (located in the campus of Paris SUD Univ., south of Paris), France.

Project description

Our lab interrogates the mechanisms of the cell to preserve genome integrity using human BRCA2 protein as a model. We are interested in the function of BRCA2 and the consequences of its mutation in breast cancer predisposition. During the last few years we have identified a new DNA binding domain in BRCA2 that is defective in breast cancer variants, defined a role of BRCA2 as mediator in meiotic recombination and contributed to the work that first describes BRCA2 hypomorphic variants conferring increased moderate risk of breast cancerRecently, we have uncovered a role of BRCA2 in mitosis that allows proper chromosome segregation. Which of the functions of BRCA2, when defective, drive tumor formation is a long-standing question that we are also investigating using functional assays and “omics” approaches.

In this project, the candidate will tackle relevant questions about the function of BRCA2 protein using cell biology and biochemistry tools.

Techniques: The project will involve cell imaging, biochemistry, protein purification, genetics, molecular biology.

Work environment

Our laboratory is part of the “Genotoxic Stress and Cancer” (UMR 3348 CNRS) Unit of the Institut Curie, Orsay site (France). The Department is dedicated to the study of the DNA damage response, genome instability, replication stress and gene regulation mechanisms in human and model organisms. The successful candidate will benefit from top-level scientific environment of Institut Curie, the expertise of the other groups working in our Unit, our collaborators on this project (Sophie Zinn-Justin, CEA, France), from state-of-the-art facilities available at Institut Curie.

Candidate requirements

  • Recent PhD with at least one first-author international publication
  • Enthusiastic and highly motivated researcher with strong interest in the mechanisms of preserving genome integrity
  • Ability to work independently
  • Excellent communication skills, fluency in English
  • The ideal candidate would have experience in one or more of the following areas: biochemistry, protein purification, cell imaging, DNA repair, molecular biology.

Following the 1-year contract, the candidate will have the opportunity to continue his/her project in the lab by applying to the different Fellowships available for postdocs (first deadline September).

To apply, please send: curriculum vitae, motivation letter and the names/contact information of 2/3 referees to Aura Carreira:   before April 30th.

The position is available immediately but the start date is flexible.

For more information about the interests of the group visit: https://science.curie.fr/equipe-carreira

Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points.

Offres d’emploi

Technical Engineer (Engineer d’étude)

Contract type: 1 year fully-funded position (possibility of renewal depending on grants)

A Technical Engineer position is available starting immediately in the Homologous Recombination and Cancerlab headed by Dr. Aura Carreira at Institut Curie, Orsay site (located in the campus of Paris SUD Univ., south of Paris), France

Description of duties:

  • Biochemical and Cell Biology based assays
  • Molecular Biology tools: PCR, cloning, mutagenesis, gene editing.
  • Generation of stable cell lines

Candidate Profile:

  • Technical Engineer (Engineer d’étude) with at least one year of experience in a Life Sciences laboratory.
  • The candidate should be fluent in English, and have excellent organizational skills.
  • Experience in one or more of the following areas: biochemistry, protein purification, cell imaging, molecular biology, mammalian cell culture.

Salary: Commensurate with qualifications and consistent with I. Curie pay scale.

How to apply: Please send your CV, motivation letter and the names/contact information of 2/3 referees to Aura Carreira:   before the 26th of April 2019.

For information about the interests of the group visit: https://science.curie.fr/equipe-carreira

Postdoctoral Position In Genome Integrity And Cancer

A 1-year fully funded postdoctoral position with the possibility of extension (see below) is available in the “Homologous Recombination and Cancer” group headed by Dr. Aura Carreira at the Institut Curie, Orsay site (located in the campus of Paris SUD Univ., south of Paris), France.

Project description

Our lab interrogates the mechanisms of the cell to preserve genome integrity using human BRCA2 protein as a model. We are interested in the function of BRCA2 and the consequences of its mutation in breast cancer predisposition. During the last few years we have identified a new DNA binding domain in BRCA2 that is defective in breast cancer variants, defined a role of BRCA2 as mediator in meiotic recombination and contributed to the work that first describes BRCA2 hypomorphic variants conferring increased moderate risk of breast cancer. Recently, we have uncovered a role of BRCA2 in mitosis that allows proper chromosome segregation. Which of the functions of BRCA2, when defective, drive tumor formation is a long-standing question that we are also investigating using functional assays and “omics” approaches.

In this project, the candidate will tackle relevant questions about the function of BRCA2 protein using cell biology and biochemistry tools.

Techniques: The project will involve cell imaging, biochemistry, protein purification, genetics, molecular biology.

Work environment

Our laboratory is part of the “Genotoxic Stress and Cancer” (UMR 3348 CNRS) Unit of the Institut Curie, Orsay site (France). The Department is dedicated to the study of the DNA damage response, genome instability, replication stress and gene regulation mechanisms in human and model organisms. The successful candidate will benefit from top-level scientific environment of Institut Curie, the expertise of the other groups working in our Unit, our collaborators on this project (Sophie Zinn-Justin, CEA, France), from state-of-the-art facilities available at Institut Curie.

Candidate requirements

  • Recent PhD with at least one first-author international publication
  • Enthusiastic and highly motivated researcher with strong interest in the mechanisms of preserving genome integrity
  • Ability to work independently
  • Excellent communication skills, fluency in English
  • The ideal candidate would have experience in one or more of the following areas: biochemistry, protein purification, cell imaging, DNA repair, molecular biology.

Following the 1-year contract, the candidate will have the opportunity to continue his/her project in the lab by applying to the different Fellowships available for postdocs (first deadline September).

To apply, please send: curriculum vitae, motivation letter and the names/contact information of 2/3 referees to Aura Carreira:  before April 30th.

The position is available immediately but the start date is flexible.

For more information about the interests of the group visit: https://science.curie.fr/equipe-carreira

For opportunities for students and postdocs interested in joining our team please read below.

Postdoctoral researchers

Interested candidates are encouraged to  including in the email a CV and 2 letters of recommendation. In a second step we will discuss possible projects and fellowships to apply for, these are some of the funding agencies that support postdocs: ARC (deadlines: approx. March 15th or September 13th), EMBO (deadlines: February 15th or August 15th), FRM (deadline: October 11th), HFSP (deadline: August 23rd), La Ligue contre le Cancer (deadlines: March 15th or September 10th), Marie Sklodowska-Curie (deadline: 14th September), Fondation de France.

PhD-students

Our group is part of the École Doctorale de Cancérologie of the University Paris-Sud XI. The candidates should subscribe to this PhD program in order to compete for a grant from the Ministry of Research after the completion of the Masters. Please  in advance if you are interested in doing a PhD in our group.

Master students

We have regularly open projects for master (M2) students in our group. Please  for more details.

Identification of three-way DNA junction ligands through screening of chemical libraries and

The human genome is replete with repetitive DNA sequences that can fold into thermodynamically stable secondary structures such as hairpins and quadruplexes. Cellular enzymes exist to cope with these structures whose stable accumulation would result in DNA damage through interference with DNA transactions such as transcription and replication. Therefore, chemical stabilization of secondary DNA structures offers an attractive way to foster DNA transaction-associated damages to trigger cell death in proliferating cancer cells. While much emphasis has been recently given to DNA quadruplexes, we focused here on three-way DNA junctions (TWJ) and report on a strategy to identify TWJ-targeting agents through a combination of in vitro techniques (TWJ-Screen, PAGE, FRET-melting, ESI-MS, dialysis equilibrium and SRB assays). We designed a complete workflow and screened 1200 compounds to identify promising TWJ-ligands selected on stringent criteria in terms of TWJ folding ability, affinity and selectivity.

CD39 Expression Defines Cell Exhaustion in Tumor-Infiltrating CD8 T Cells-Response.

IL2/Anti-IL2 Complex Combined with CTLA-4, But Not PD-1, Blockade Rescues Antitumor NK Cell

High-dose IL2 immunotherapy can induce long-lasting cancer regression but is toxic and insufficiently efficacious. Improvements are obtained with IL2/anti-IL2 complexes (IL2Cx), which redirect IL2 action to CD8 T and natural killer (NK) cells. Here, we evaluated the efficacy of combining IL2Cx with blockade of inhibitory immune pathways. In an autochthonous lung adenocarcinoma model, we show that the IL2Cx/anti-PD-1 combination increases CD8 T-cell infiltration of the lung and controls tumor growth. In the B16-OVA model, which is resistant to checkpoint inhibition, combination of IL2Cx with PD-1 or CTLA-4 pathway blockade reverses that resistance. Both combinations work by reinvigorating exhausted intratumoral CD8 T cells and by increasing the breadth of tumor-specific T-cell responses. However, only the IL2Cx/anti-CTLA-4 combination is able to rescue NK cell antitumor function by modulating intratumoral regulatory T cells. Overall, association of IL2Cx with PD-1 or CTLA-4 pathway blockade acts by different cellular mechanisms, paving the way for the rational design of combinatorial antitumor therapies.

CD16NKG2A Natural Killer Cells Infiltrate Breast Cancer-Draining Lymph Nodes.

Tumor-draining lymph nodes (TD-LNs) are the first site of metastasis of breast cancer. Natural killer (NK) cells that infiltrate TD-LNs [including noninvaded (NI) or metastatic (M)-LNs from breast cancer patients] and NK cells from healthy donor (HD)-LNs were characterized, and their phenotype analyzed by flow cytometry. Low percentages of tumor cells invaded M-LNs, and these cells expressed ULBP2 and HLA class I molecules. Although NK cells from paired NI and M-LNs were similar, they expressed different markers compared with HD-LN NK cells. Compared with HD-LNs, TD-LN NK cells expressed activating DNAM-1, NKG2C and inhibitory NKG2A receptors, and exhibited elevated CXCR3 expression. CD16, NKG2A, and NKp46 expression were shown to be increased in stage IIIA breast cancer patients. TD-LNs contained a large proportion of activated CD56CD16 NK cells with high expression of NKG2A. We also showed that a subset of LN NK cells expressed PD-1, expression of which was correlated with NKp30 and NKG2C expression. LN NK cell activation status was evaluated by degranulation potential and lytic capacity toward breast cancer cells. NK cells from TD-LNs degranulated after coculture with breast cancer cell lines. Cytokine-activated TD-LN NK cells exerted greater lysis of breast cancer cell lines than HD-LN NK cells and preferentially lysed the HLA class I MCF-7 breast cancer cell line. TD-LNs from breast cancer patients, thus, contained activated lytic NK cells. The expression of inhibitory receptor NKG2A and checkpoint PD-1 by NK cells infiltrating breast cancer-draining LNs supports their potential as targets for immunotherapies using anti-NKG2A and/or anti-PD-1.

Let me in: Control of HIV nuclear entry at the nuclear envelope.

The nuclear envelope is a physical barrier that isolates the cellular DNA from the rest of the cell, thereby limiting pathogen invasion. The Human Immunodeficiency Virus (HIV) has a remarkable ability to enter the nucleus of non-dividing target cells such as lymphocytes, macrophages and dendritic cells. While this step is critical for replication of the virus, it remains one of the less understood aspects of HIV infection. Here, we review the viral and host factors that favor or inhibit HIV entry into the nucleus, including the viral capsid, integrase, the central viral DNA flap, and the host proteins CPSF6, TNPO3, Nucleoporins, SUN1, SUN2, Cyclophilin A and MX2. We review recent perspectives on the mechanism of action of these factors, and formulate fundamental questions that remain. Overall, these findings deepen our understanding of HIV nuclear import and strengthen the favorable position of nuclear HIV entry for antiviral targeting.

Hepatitis B Virus Evasion From Cyclic Guanosine Monophosphate-Adenosine Monophosphate Synthase

Chronic hepatitis B virus (HBV) infection is a major cause of chronic liver disease and cancer worldwide. The mechanisms of viral genome sensing and the evasion of innate immune responses by HBV infection are still poorly understood. Recently, the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) was identified as a DNA sensor. In this study, we investigated the functional role of cGAS in sensing HBV infection and elucidate the mechanisms of viral evasion. We performed functional studies including loss-of-function and gain-of-function experiments combined with cGAS effector gene expression profiling in an infectious cell culture model, primary human hepatocytes, and HBV-infected human liver chimeric mice. Here, we show that cGAS is expressed in the human liver, primary human hepatocytes, and human liver chimeric mice. While naked relaxed-circular HBV DNA is sensed in a cGAS-dependent manner in hepatoma cell lines and primary human hepatocytes, host cell recognition of viral nucleic acids is abolished during HBV infection, suggesting escape from sensing, likely during packaging of the genome into the viral capsid. While the hepatocyte cGAS pathway is functionally active, as shown by reduction of viral covalently closed circular DNA levels in gain-of-function studies, HBV infection suppressed cGAS expression and function in cell culture models and humanized mice. Conclusion: HBV exploits multiple strategies to evade sensing and antiviral activity of cGAS and its effector pathways.

NONO Detects the Nuclear HIV Capsid to Promote cGAS-Mediated Innate Immune Activation.

Detection of viruses by innate immune sensors induces protective antiviral immunity. The viral DNA sensor cyclic GMP-AMP synthase (cGAS) is necessary for detection of HIV by human dendritic cells and macrophages. However, synthesis of HIV DNA during infection is not sufficient for immune activation. The capsid protein, which associates with viral DNA, has a pivotal role in enabling cGAS-mediated immune activation. We now find that NONO is an essential sensor of the HIV capsid in the nucleus. NONO protein directly binds capsid with higher affinity for weakly pathogenic HIV-2 than highly pathogenic HIV-1. Upon infection, NONO is essential for cGAS activation by HIV and cGAS association with HIV DNA in the nucleus. NONO recognizes a conserved region in HIV capsid with limited tolerance for escape mutations. Detection of nuclear viral capsid by NONO to promote DNA sensing by cGAS reveals an innate strategy to achieve distinction of viruses from self in the nucleus.